foundling

n (arch 古) abandoned child of unknown parents who is found by sb 弃儿.

fossilization, fossilisation, fossilize, fossilize, fossilise, foster, foster-, fought, foul, foul play, foul-mouthed, foul-up, foully, foulness, found, foundation, foundation course, foundation-stone, foundations, founder, founder-member, founding father, foundry, fount, fountain, fountain-head, fountain-pen, four, four-, four-in-hand, four-letter word, four-ply, four-poster, four-square, four-wheel drive, fourfold, foursome, fourteen, fourteenth, fourth, fowl, fowl pest,