fog-horn

n instrument that makes a loud blaring noise to warn ships of danger when it is foggy 雾角; 雾号; 雾笛: (joc or derog 谑或贬) He's got a voice like a fog-horn, ie a loud, harsh voice. 他的嗓音像雾角（大而刺耳）.

FM, FO, foal, foam, foamy, fob, focal, focal length (also focal distance), focal point, focsle, focus, focus on, focus...on, fodder, foe, foetal (US fetal), foetus (US fetus), fog, fog-bank, fog-bound, fog-lamp, foggy, fogy (also fogey), foible, foil, foist, fold, foldaway, folder, folding, foliage, folio, folk, folk-dance, folk-music (also folk), folk-song, folk-tale, folklore, folklorist, folks, folksy,