| Term | Definition |
| frugal | Economical. |
| fruition | Fulfillment. |
| fugacious | Fleeting. |
| fulcrum | The support on or against which a lever rests, or the point about which it turns. |
| fulminate | To cause to explode. |
| fulsome | Offensive from excess of praise or commendation. |
| fumigate | To subject to the action of smoke or fumes, especially for disinfection. |
| functionary | An official. |
| fundamental | Basal. |
| fungible | That may be measured, counted, or weighed. |
| fungous | Spongy. |
| fungus | A plant destitute of chlorophyll, as a mushroom. |
| furbish | To restore brightness or beauty to. |
| furlong | A measure, one-eighth of a mile. |
| furlough | A temporary absence of a soldier or sailor by permission of the commanding officer. |
| furrier | A dealer in or maker of fur goods. |
| further | More distant or advanced. |
| furtherance | Advancement. |
| furtive | Stealthy or sly, like the actions of a thief. |
| fuse | To unite or blend as by melting together. |
| fusible | Capable of being melted by heat. |
| futile | Of no avail or effect. |
| futurist | A person of expectant temperament. |
| gauge | An instrument for measuring. |
| gaiety | Festivity. |
| gaily | Merrily. |
| gait | Carriage of the body in going. |
| gallant | Possessing a brave or chivalrous spirit. |
| galore | Abundant. |
| galvanic | Pertaining or relating to electricity produced by chemical action. |
| galvanism | Current electricity, especially that arising from chemical action. |
| galvanize | To imbue with life or animation. |
| gamble | To risk money or other possession on an event, chance, or contingency. |
| gambol | Playful leaping or frisking. |
| gamester | A gambler. |
| gamut | The whole range or sequence. |
| garnish | In cookery, to surround with additions for embellishment. |
| garrison | The military force stationed in a fort, town, or other place for its defense. |
| garrote | To execute by strangling. |
| garrulous | Given to constant trivial talking. |
| gaseous | Light and unsubstantial. |
| gastric | Of, pertaining to, or near the stomach. |
| gastritis | Inflammation of the stomach. |
| gastronomy | The art of preparing and serving appetizing food. |
| gendarme | In continental Europe, particularly in France, a uniformed and armed police officer. |
| genealogy | A list, in the order of succession, of ancestors and their descendants. |
| genealogist | A tracer of pedigrees. |
| generality | The principal portion. |
| generalize | To draw general inferences. |
| generally | Ordinarily. |