1. 
2. 
[syn: strange, unusual]
3.  not commonly encountered; 
- Example: "two-career families are no longer unusual"
The Collaborative International Dictionary of English v.0.48:
Unusual \Un*u"su*al\, a.
   Not usual; uncommon; rare; as, an unusual season; a person of
   unusual grace or erudition. -- Un*u"su*al*ly, adv. --
   Un*u"su*al*ness, n.
   [1913 Webster]
WordNet (r) 3.0 (2006):
unusual
    adj 1: not usual or common or ordinary; "a scene of unusual
           beauty"; "a man of unusual ability"; "cruel and unusual
           punishment"; "an unusual meteorite" [ant: usual]
    2: being definitely out of the ordinary and unexpected; slightly
       odd or even a bit weird; "a strange exaltation that was
       indefinable"; "a strange fantastical mind"; "what a strange
       sense of humor she has" [syn: strange, unusual] [ant:
       familiar]
    3: not commonly encountered; "two-career families are no longer
       unusual"
Moby Thesaurus II by Grady Ward, 1.0:
52 Moby Thesaurus words for "unusual":
   almost unheard-of, atypical, bizarre, breakaway, curious,
   different, eccentric, exceptional, extraordinary, extremely,
   freakish, infrequent, novel, odd, oddball, offbeat, original,
   outlandish, peculiar, quaint, queer, rare, rarely, recherche,
   remarkable, scarce, seldom met with, seldom seen, singular, slow,
   sparse, strange, sui generis, uncommon, uncommonly, unconventional,
   uncustomary, undreamed-of, unexpected, unfamiliar, unfrequent,
   unheard-of, unimaginable, unique, unordinary, unorthodox,
   unprecedented, unthinkable, unthought-of, untypical, unusually,
   unwonted