WordNet (r) 3.0 (2006):

manana
    n 1: an indefinite time in the future

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "manana":
   after a time, after a while, aftertime, afterward, afterwards,
   afteryears, anon, before long, by and by, by destiny, by-and-by,
   course ahead, crystal ball, determinism, distant future,
   eventuality, expectation, fatally, foresight, forward look, future,
   future tense, futurism, futurity, hereafter, hopefully,
   immediate future, immediate prospect, imminence, imminently,
   in aftertime, in the future, later, near future, offing, outlook,
   posteriority, predictably, prediction, probability, probably,
   project, prophecy, prospect, proximo, soon, the future, the morrow,
   the sweet by-and-by, time ahead, time just ahead, time to come,
   tomorrow