A sudden motion downward
plunge, leap, spring, nosedive, headlong leap, headlong jump, pitch, ducking, swoop, dip, cannonball, jackknife, swan dive, header*, belly-flop*, belly-whopper*; see also fall 1, jump 1.
*An establishment offering accommodation
bar, saloon, pub, café, cabaret, hotel, motel, pizza parlor, tavern, inn, club, casino, pool hall, billiard parlor, bowling alley, nightclub, diner, coffeehouse, dancehall, hamburger joint, joint*, dump*, dine and dance*, flophouse*, fleabag*, hole*, hangout*; see also bar 2, casino, restaurant.