This list includes 40 Prefixes that start with F, from “fac-” to “fusi-“. They are mostly Latin and Greek in origin and appear in numeric, negational, spatial, medical, and technical vocabulary.
Prefixes that start with F are short word parts added at the front to change meaning or function. Many entered English via Latin or Greek and often show up in scientific and everyday words.
Below you’ll find the table with Prefix, Origin, Meaning, Examples, and Notes.
Prefix: The written form of the prefix; you use it to spot root combinations and to build or analyze words.
Origin: Language source such as Latin or Greek; this helps you trace historical meaning and related forms across words.
Meaning: Concise semantic gloss of the prefix in three to seven words, so you can quickly grasp its usual sense.
Examples: Two to four clear example words showing the prefix in context, so you see how usage affects meaning.
Notes: Short comments on register, frequency, or special senses that help you choose the right prefix in writing.
Prefixes that start with F
| Prefix | Origin | Meaning | Example words |
|---|---|---|---|
| fore- | Old English | before, in front of | foreword, foresee, forearm |
| for- | Old English | against, away, completely | forget, forbid, forswear |
| femto- | Danish/SI | 10^-15 | femtosecond, femtometer, femtomolar |
| ferro- | Latin | iron (metal) | ferromagnetism, ferroalloy, ferrocyanide |
| ferri- | Latin | iron (Fe3+) | ferrimagnetism, ferric, ferrite |
| fluoro- | Greek/Latin | fluorine, fluoride | fluorocarbon, fluoridation, fluoroscope |
| fluor- | Greek/Latin | fluorine, bright | fluoride, fluorescent, fluorometer |
| fibro- | Latin | fiber | fibroblast, fibrosis, fibroid |
| flexi- | Latin/English | flexible, adaptable | flexitime, flexitarian, flexi-plan |
| flor- | Latin | flower | floral, flora, floriculture |
| flori- | Latin | flower | floriculture, floriferous, florilegium |
| foli- | Latin | leaf | foliage, foliate, folio |
| fungi- | Latin | fungus | fungicide, fungal, fungivore |
| fili- | Latin | son, child | filial, filicide, filiation |
| fide- | Latin | faith, trust | fidelity, fideism, infidel |
| fin- | Latin | end, limit | final, finite, finish |
| flu- | Latin | flow | fluid, fluent, flux |
| flux- | Latin | flow, flowing | influx, reflux, efflux |
| fusi- | Latin | pour, melt | fusion, fusiform, effusive |
| frater- | Latin | brother | fraternity, fratricide, fraternize |
| fract- | Latin | break | fracture, fraction, fractal |
| frag- | Latin | break | fragile, fragment, fragmentation |
| fructo- | Latin | fruit | fructose, fructify, fructiferous |
| fug- | Latin | flee, put to flight | fugitive, centrifuge, subterfuge |
| furc- | Latin | forked, fork | furcate, bifurcate, furcation |
| faux- | French | false, imitation | faux pas, faux fur, fauxhawk |
| filtr- | Latin | strain, filter | filtration, filtrate, filterable |
| fenestr- | Latin | window, opening | fenestration, fenestra, fenestrate |
| fulg- | Latin | lightning, flash | fulgurite, fulguration, refulgent |
| fecund- | Latin | fertile, fruitful | fecundity, fecundate, fecund |
| fric- | Latin | rub, rub away | friction, fricative, frication |
| foss- | Latin | dig up, ditch | fossil, fossilize, fossiliferous |
| form- | Latin | shape, form | formation, formative, deform |
| forti- | Latin | strong | fortify, fortitude, fortress |
| fac- | Latin | make, do | factory, manufacture, facilitate |
| frigor- | Latin | cold | frigorific, frigorimeter, frigorostat |
| femin- | Latin | woman, female | feminism, feminine, feminist |
| flav- | Latin | yellow | flavonoid, flavoprotein, flavone |
| funct- | Latin | perform, execute | function, malfunction, functional |
| ferv- | Latin | boil, glow | fervent, fervid, effervescent |
Descriptions
fore-
Very common Old English prefix meaning “before” or “in front of”; highly productive in timing and position words.
for-
Old English verbal prefix with senses “against/away/utterly”; appears in many verbs (sometimes confused with preposition “for”).
femto-
SI metric prefix (from Danish “femten” = fifteen); widely used in physics and chemistry for extremely small scales.
ferro-
Chemical/materials combining form indicating metallic iron or iron-containing materials.
ferri-
Variant seen in chemical nomenclature (often used for iron in a particular oxidation state).
fluoro-
Common chemical prefix for fluorine-containing compounds; frequent in pharmaceuticals and materials science.
fluor-
Alternative combining form to fluoro-; appears in everyday and technical vocabulary.
fibro-
Biomedical prefix for connective tissue or fibers; common in pathology and cell biology.
flexi-
Modern English combining form denoting flexibility; informal and business-friendly usage.
flor-
Classical combining form meaning “flower,” frequent in botany and decorative contexts.
flori-
Variant of flor- used before vowels; common in botanical and literary compounds.
foli-
Combining form for “leaf” used in botany and publishing terminology.
fungi-
Biological combining form for fungus-related terms (often seen in microbiology and agriculture).
fili-
Combining form meaning child or descendant; appears in legal, social, and kinship terms.
fide-
Classical combining form for faith/trust; appears in technical and motto contexts.
fin-
Combining form meaning “end” or “limit”; common in everyday and formal vocabulary.
flu-
Classic combining form meaning “to flow”; underlies many words about movement or smoothness.
flux-
Variant combining form used in contexts of movement or transfer.
fusi-
From fundere “to pour”; used in chemistry and descriptive morphology.
frater-
Root for “brother”; common in social, legal, and historical terms.
fract-
Combining form from frangere “to break”; used in science, math, and everyday vocabulary.
frag-
Alternate combining form related to breaking or shattering.
fructo-
Botanical and chemical combining form meaning “fruit” or fruit-bearing.
fug-
From fugere “to flee”; appears in legal, musical, and technical words (and some chemistry).
furc-
Technical combining form meaning forked or branched; used in biology and morphology.
faux-
Borrowed French element used stylistically to mean “fake” or “imitation”; common in fashion and colloquial English.
filtr-
Combining form for filtering/straining processes; common in engineering and lab contexts.
fenestr-
Architectural and anatomical combining form referring to openings or windows.
fulg-
Rare literary/technical combining form meaning to flash or shine (from fulgur “lightning”).
fecund-
Scholarly combining form meaning fertile or productive; common in biology and literary usage.
fric-
Combining form from fricare “to rub”; used in physics and phonetics.
foss-
Geological combining form from fodere “to dig,” used in paleontology and geology.
form-
Highly productive combining form meaning shape or structure; used across disciplines.
forti-
Combining form from fortis “strong”; found in many words about strength or defense.
fac-
Extremely common Latin combining form (fac-/fact-) meaning “make” or “do”; appears in many English derivatives.
frigor-
Rare technical combining form for cold; shows up in specialized technical vocabulary.
femin-
Productive combining form for female/women-related terms across social and political contexts.
flav-
Biochemical combining form meaning yellow or yellowish; common in natural-product chemistry.
funct-
Combining form from fungor/funcio meaning “to perform”; frequent in technical and everyday English.
ferv-
Combining form related to heat or intensity; common in descriptive and figurative uses.