WordWeb Online

1. Marked by or producing unhappiness
   "infelicitous circumstances";
   - unhappy
    
2. Not appropriate in application; defective
   "an infelicitous remark"; "infelicitous phrasing"; "the infelicitous typesetting was due to illegible copy"

See also: awkward, clumsy, clunky [informal], cumbersome, felicitousness, felicity, ill-chosen, inapt, inept, unfortunate, unhappy

Antonym: felicitous

Encyclopedia: Infelicitous