| enervative(adjective, dull, boring, tired, tedious) |
| everyday(adjective, dull, simple, clean, plain) |
| exacting(adjective, dull, boring, tired, tedious) |
| exasperate(verb, worry, fail, strain, annoy) |
| exasperating(adjective, dull, boring, tired, tedious) |
| exhaust(verb, fail, strain, annoy, drain) |
| exhausting(adjective, dull, boring, tired, tedious) |
| factual(adjective, simple, flat, clean, plain) |
| fag(verb, worry, fail, strain, annoy) |
| fail(verb, strain, annoy, irritate, exhaust) |
| fall asleep(expression, idiom, rest, relax, retire) |
| fall out(expression, rest, relax, retire, languish) |
| fatigue(noun, verb, worry, fail, strain) |
| fatigue catch flies(verb, expression, idiom, sign, stretch) |
| fatiguing(adjective, dull, boring, tired, tedious) |
| fenestra |
| fistula |
| flat(adjective, dull, quiet, simple, slow) |
| flat tire(noun, expression, bother, drag, nuisance) |
| flatness(noun, melancholy, dullness, apathy, indifference) |