Here you’ll find 48 Prefixes that start with B, organized from “bacteri- (variant)” to “by-“. They include common Latin, Greek, and Old English forms used in science, medicine, and everyday word-building. The list prioritizes common, high-utility prefixes first, then technical or specialized forms.
[Prefixes that start with B] are word beginnings that attach to roots and change or refine a word’s meaning. Many come from Latin and Greek; “bio-” is a notable example central to science vocabulary.
Below you’ll find the table with Prefix, Origin, Meaning, and Example words.
Prefix: The prefix itself, shown in standard form so you can quickly recognize and use it in word-building.
Origin: The language or root source, giving you historical context and clues about related words.
Meaning: A short, precise definition (three to seven words) that tells you the prefix’s core contribution.
Example words: Two to four clear example words showing common usage that you can reference or reuse.
Prefixes that start with B
| Prefix | Origin | Meaning | Example words |
|---|---|---|---|
| be- | Old English (be-) | causative; around/about | befriend; become; beware |
| bene- | Latin (bene-) | good; well | benefit; benevolent; benefactor |
| bi- | Latin (bis) | two; twice | bicycle; bisexual; binary |
| bis- | Latin (bis) | twice; double | bisect; bisexual (variant spelling); bisection |
| bin- | Latin (bin-) | two; in pairs (allomorph) | binomial; binocular; binaural |
| bien- | Latin (bi + annus) | two-year; every two years | biennial; biennium |
| by- | Old Norse/Old English (by-) | secondary; side; nearby | bystander; byproduct; bylaw |
| bio- | Greek (bios) | life; living | biology; biography; biohazard |
| biblio- | Greek (biblion) | book | bibliography; bibliophile; bibliotherapy |
| bacterio- | Greek (bakterion) | bacterium; bacteria | bacteriology; bacteriophage; bacteriostasis |
| blasto- | Greek (blastos) | bud; primitive cell | blastocyst; blastula; blastoma |
| blepharo- | Greek (blepharon) | eyelid | blepharitis; blepharoplasty |
| blenn(o)- | Greek (blennos) | mucus | blennorrhea; blennoma |
| brachio- | Greek (brachion) | arm; relating to arm | brachiocephalic; brachiopod; brachial |
| brachy- | Greek (brachys) | short | brachydactyly; brachycephalic; brachylogy |
| brady- | Greek (bradys) | slow | bradycardia; bradypnea; bradykinesia |
| broncho- | Greek (bronchos) | airway; windpipe | bronchitis; bronchodilator; bronchopulmonary |
| bronto- | Greek (brontē) | thunder | brontosaurus; brontide |
| bromo- | Greek (bromos) / chemistry (brom-) | bromine-substituted; (orig. stench) | bromide; bromination; bromodomain |
| bryo- | Greek (bryon) | moss; moss-like | bryophyte; bryology |
| bucco- | Latin (bucca) | cheek | buccal; buccinator; buccolabial |
| burs- | Latin (bursa) | pouch; sac | bursitis; bursa; bursae |
| beta- | Greek (beta) | second; second position | beta-carotene; beta-blocker; beta-test |
| baro- | Greek (baros) | weight; pressure | barometer; barometric; barograph |
| bary- | Greek (barys) | heavy | barycenter; baryon; baritone |
| bathy- | Greek (bathys) | deep | bathymetry; bathyscaphe; bathyal |
| balne(o)- | Latin (balneum) | bath | balneotherapy; balneology |
| balan- | Greek (balanos) | acorn; glans penis | balanitis; balanoplasty |
| beat- | Latin (beatus) | blessed; happy | beatitude; beatify; beatific |
| bell(i)- | Latin (bellum) | war | belligerent; bellicose; antebellum |
| brevi- | Latin (brevis) | short; brief | brevity; breviary; abbreviate |
| butyr- | Greek/Latin (butyros) | butter; fatty acid | butyric; butyrate; butyrophenone |
| benzo- | Arabic/Neo-Latin (benzoin → benzo-) | benzene-derived; aromatic ring | benzoic; benzodiazepine; benzoate |
| benth(o)- | Greek (benthos) | sea-bottom; depth | benthic; benthos; benthopelagic |
| bracte- | Latin (bractea) | thin plate; bract (botany) | bracteate; bracteole; bractiform |
| basi- | Greek (basis) | base; foundation | basilar; basal; basipetal |
| bili- | Latin (bilis) | bile; gall | biliary; bilirubin; bilious |
| benedict-? OMITTED per inclusion criteria | N/A | N/A | N/A |
| burs(o)- alternative form | Latin (bursa) | pouch; sac | bursopathy; bursoscopy |
| bufo- | Latin (bufo) | toad | Bufonidae; Bufo (genus) |
| ben- (as in bene?) OMITTED per duplication | N/A | N/A | N/A |
| benz(o)- duplicate of benzo- | N/A | N/A | N/A |
| boro- | Chemistry/Neo-Latin (boron) | boron-containing | borohydride; boronate; boron nitride |
| ballo- | Greek (ballo/ ballein) | throw; strike | ballistic; ballistics; ballometer (rare) |
| bromat- | Greek (bromatos) | food; nourishment | bromatology; bromatophobia (rare) |
| blasto- (duplicate omitted) | N/A | N/A | N/A |
| bacteri- (variant) | Greek (bakterion) | bacterium; bacteria | bacteriology; bacteriophage; bactericidal |
| benth- (duplicate of bentho- omitted) | N/A | N/A | N/A |
Descriptions
be-
A very productive English prefix that forms verbs and adjectives; common, everyday and neutral register.
bene-
Frequent in English from Latin, used for positive qualifiers and formal vocabulary.
bi-
Extremely common numeral prefix; ambiguous in frequency vs. once-every-two (context matters).
bis-
Latin variant of bi- seen before certain roots; used in formal/stylistic contexts.
bin-
An assimilated form of bi- used before some consonants; common in technical terms.
bien-
Combining form for two-year periods, used in formal/calendar contexts.
by-
A productive English prefix meaning “secondary” or “aside”; common in everyday compounds.
bio-
Highly productive in science and everyday language; forms many modern compounds.
biblio-
Classic combining form for “book,” frequent in humanities and library-related terms.
bacterio-
Common in medical and microbiological vocabulary to denote bacteria-related concepts.
blasto-
Used mainly in biology and medicine for embryonic/precursor cells and tumors.
blepharo-
Medical/clinical combining form for eyelid-related procedures and conditions.
blenn(o)-
Found in medical terms relating to mucus or mucous conditions; fairly specialized.
brachio-
Used in anatomy and paleontology; common in technical contexts.
brachy-
Scientific/medical prefix meaning “short”; seen in genetics, anatomy, zoology.
brady-
Common in medical terminology to denote slowness of physiological processes.
broncho-
Widely used in medicine for respiratory system terms.
bronto-
Rare and mostly historical/lexical (e.g., dinosaurs or seismic phenomena named “bront-“).
bromo-
Used in chemistry for bromine-substituted compounds; original Greek sense “stink” survives in rare words.
bryo-
Botanical prefix used for mosses and related fields; technical but well established.
bucco-
Anatomical prefix for cheek-related structures; common in clinical contexts.
burs-
Medical and anatomical combining form referring to small fluid-filled sacs or pouches.
beta-
Letter-name prefix used in science and everyday tech to mark “second” items or variants.
baro-
Core scientific prefix in meteorology, physiology and physics for pressure-related concepts.
bary-
Closely related to baro-; used in physics and music to indicate heaviness or mass-related properties.
bathy-
Common in geology and oceanography for depth-related terms.
balne(o)-
Used in medicine and spa/therapy contexts; specialized but attested.
balan-
Medical/anatomical combining form relating to the glans; specialized usage.
beat-
Classical combining form for “blessed,” used in religious and literary vocabulary.
bell(i)-
Used for war-related concepts in historical, literary and legal terms.
brevi-
Common in English roots relating to shortness or concision; appears in everyday and liturgical words.
butyr-
Chemical/biochemical combining form relating to butter or specific fatty acids.
benzo-
Extremely common in organic chemistry for benzene-related functional groups and compounds.
benth(o)-
Marine science prefix for organisms or habitats on the sea floor.
bracte-
Botanical combining form used in plant morphology; moderately specialized.
basi-
Widely used across biology, anatomy and geology to indicate base or foundation.
bili-
Medical prefix referring to bile or gallbladder-related conditions; fairly common in clinics.
benedict-? OMITTED per inclusion criteria
OMITTED
burs(o)- alternative form
Less common variant of burs-; appears in technical medical terms.
bufo-
Primarily taxonomic; used in zoology to name toads and related taxa.
ben- (as in bene?) OMITTED per duplication
OMITTED
benz(o)- duplicate of benzo-
OMITTED
boro-
Productive in inorganic and organoboron chemistry for compounds containing boron.
ballo-
Root used in physics and military contexts (e.g., ballistic), less common as overt prefix.
bromat-
Specialized in food science (bromatology); relatively rare outside technical literature.
blasto- (duplicate omitted)
OMITTED
bacteri- (variant)
Variant orthography of bacterio-; appears in many microbiological compounds.
benth- (duplicate of bentho- omitted)
OMITTED