WordNet (r) 3.0 (2006):

last minute
    n 1: the latest possible moment; "money became available at the
         eleventh hour"; "at the last minute the government changed
         the rules" [syn: eleventh hour, last minute]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "last minute":
   belatedness, cursory, deathbed, eleventh hour, eleventh-hour,
   expeditious, festinate, feverish, flying, furious, hasty,
   high time, hurried, immediate, instant, late hour, lateness, later,
   on the spot, passing, prompt, quick, slap-bang, slapdash,
   small hours, snap, speedy, superficial, swift, tardiness,
   unpreparedness, unpunctuality, unreadiness, untimeliness, urgent