| Term | Definition |
| flippant | lacking proper seriousness |
| flit | fly; dart lightly; pass swiftly by |
| floe | mass of floating ice |
| flora | plants of region or era |
| florid | ruddy; reddish; flowery |
| flotsam | drifting wreckage |
| flounder | struggle and thrash about; proceed clumsily |
| flourish | grow well; prosper; make sweeping gestures |
| flout | reject; mock; show contempt for |
| fluctuate | waver; shift |
| fluency | smoothness of speech |
| fluke | a chance occurrence; accident; stroke of fortune |
| fluster | confuse |
| fluted | having vertical parallel groove ( as in a pillar) |
| flux | flowing; series of changes |
| fodder | coarse food for cattle, horses, etc. |
| foible | weakness; slight fault |
| foil | defeat; frustrate |
| foist | insert improperly; palm off |
| foliage | masses of leaves |
| foment | stir up; instigate |
| foolhardy | rash |
| fop | dandy; man excessively preoccupied with his clothes |
| foray | raid |
| forbearance | patience |
| ford | place where a river can be crossed on foot |
| forebears | ancestors |
| foreboding | premonition of evil |
| forensic | suitable to debate or courts of law |
| foreshadow | give an indication beforehand; portend; prefigure |
| foresight | ability to foresee future happenings; prudence |
| forestall | prevent by taking an action in advance |
| forgo | give up; do with out |
| forlorn | sad and lonely; wretched |
| formality | ceremonious quality; something done just for form's sake |
| formidable | inspiring fear or apprehension; difficult; awe-inspiring |
| forsake | desert; abandon |
| forswear | renounce; abandon |
| forte | strong point or special talent |
| forthright | straight forward; direct; frank |
| fortitude | bravery; courage |
| fortuitous | accidental; by chance |
| foster | rear; encourage |
| founder (v) | fail completely; sink |
| founder (n) | person who establishes ( an organization, business) |
| fracas | brawl, melee |
| fractious | unruly; disobedient; irritable |
| frail | weak |
| franchise | right granted by authority; right to vote; license to sell a product in a particular territory |
| frantic | wild |
| fraudulent | cheating; deceitful |
| fraught | filled or charged with; causing emotional distress |
| fray | brawl |
| frenetic | frenzied; frantic |
| frenzied | madly excited |
| fresco | painting on a plaster |
| fret | be annoyed or vexed |
| friction | clash in opinion; run against |
| frieze | ornamental band on the wall |
| frigid | intensely cold |
| fritter | waste |
| frivolous | lacking in seriousness; self indulgently carefree; relatively unimportant |
| frolicsome | prankish, gay |
| frond | fern leaf; palm or banana leaf |
| froward | stubbornly contrary; obstinately disobedient |
| fructify | bear fruit |
| frugality | thrift; economy |
| fruition | bearing of fruit; fulfillment; realization |
| frustrate | To prevent from accomplishing a purpose or fulfilling a desire; thwart; defeat; to cause feeling of discouragement |
| fugitive | fleeting or transitory; roving |
| fulcrum | support on which a lever rests |
| fulminate | denounce thunderously; explode |
| fulsome | disgustingly excessive |
| functionary | official |
| fundamental | basic; primary; essential |
| funereal | sad; solemn |
| furor | frenzy; great excitement |
| furtive | stealthy; sneaky |
| fusillade | simultaneously firing or outburst ( of missiles, questions e t c) |
| fusion | union; blending; synthesis |
| futile | useless; hopeless; ineffectual |
| gadfly | animal-biting fly; an irritating person |
| gaffe | social blunder |