The Collaborative International Dictionary of English v.0.48:

Felicitous \Fe*lic"i*tous\, a.
   Characterized by felicity; happy; prosperous; delightful;
   skillful; successful; happily applied or expressed;
   appropriate.
   [1913 Webster]

         Felicitous words and images.             --M. Arnold.
   -- Fe*lic"i*tous*ly, adv. -- Fe*lic"i*tous*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

felicitous
    adj 1: exhibiting an agreeably appropriate manner or style; "a
           felicitous speaker" [ant: infelicitous]
    2: marked by good fortune; "a felicitous life"; "a happy
       outcome" [syn: felicitous, happy]