Founder. Originator, institutor, establisher, planter; molder, caster; author.
Ant. Subverter, destroyer.
Fountain. Spring, well, jet; source, origin, original cause, first principle.
Fraction. Part, portion, fragment, piece, bit, scrap, section.
Ant. Whole, total, amount, sum, aggregate.
Fractious. Cross, captious, petulant, testy, peevish, fretful, irritable, waspish, snappish; pettish.
Ant. Good-humored, blithesome, agreeable, complaisant, genial.
Fragile. Brittle, easily broken, frangible; infirm, frail, weak, feeble, delicate, slight.
Ant. Tough, hardy, stout, strong.
Fragment. Remnant, fraction, scrap, chip, detached part, bit, piece, morsel.