| Term | Definition |
| Fabricate | To make or devise; construct |
| Facade | Face, front; mask, superficial appearance |
| Facile | Very easy |
| Fallacious | Wrong, unsound, illogical |
| Fallow | Uncultivated, unused |
| Fanaticsm | Extreme devotion to a cause |
| Farcical | Absurd, ludicrous |
| Fastidious | Careful with details |
| Fathom | To measure the depth of, gauge |
| Fatuous | Stupid; foolishly self-satisfied |
| Fawn | To flatter excessively, seek the favor or |
| Faze | To bother, upset, or disconcert |
| Feckless | Ineffective, careless, irresponsible |
| Feign | To pretend, give a false impression; to invent falsely |
| Felicitous | Suitable, appropriate; well-spoken |
| Fell | To chop, cut down |
| Fervid | Passionate, intense, zealous |
| Fetid | Foul-smelling, failure |
| Fidelity | Loyalty |
| Finicky | Fussy, difficult to please |
| Fiasco | Disaster, utter failure |
| Fetid | Foul-smelling, putrid |
| Flaccid | Limp, flabby, weak |
| Flagrant | Outrageous, shameless |
| Flamboyant | Flashy, garish; exciting, dazzling |
| Flaunt | To show off |
| Flora | Plants |
| Florid | Gaudy, extremely ornate; ruddy, flushed |
| Flounder | To falter, waver; to muddle, struggle |
| Flout | To treat contemptuously, scorn |
| Fluctuate | To alternate, waver |
| Foible | Minor weakness or character flaw |
| Foil | To defeat, frustrate |
| Foment | To arouse or incite |
| Ford | To cross a body of water at a shallow place |
| Foreboding | Dark sense of evil to come |
| Forestall | To prevent, delay; anticipate |
| Forethought | Anticipation, foresight |
| Forgo | To go without, refrain from |
| Forlorn | Dreary, deserted; unhappy; hopeless, despairing |
| Forswear | To repudiate, renounce, disclaim, reject |
| Forte | Strong point, something a person does well |
| Fortuitous | Happening by luck, fortunate |
| Foster | To nourish, cultivate, promote |
| Founder | To fall helplessly; sink; fail |
| Fracas | Noisy dispute |
| Fractious | Unruly, rebellious |
| Fraudulent | Deceitful, dishonest, unethical |
| Fraught | Full of, accompanied by |
| Frenetic | Wildly frantic, frenzied, hectic |
| Fulsome | Sickeningly excessive; repulsive |
| Funeral | Mournful, appropriate to a funeral |
| Furtive | Secret, stealthy |