25 Moby Thesaurus words for "spring upon": ambush, astonish, bushwhack, catch at, catch off-guard, catch unawares, come from behind, come upon unexpectedly, do the unexpected, drop in on, fasten upon, jump, jump at, pounce upon, pull up short, scramble for, seize on, snap at, snatch at, spring a surprise, surprise, swoop down upon, take by surprise, take short, take unawares