[1] : WordNet (r) 2.0

fit in
     v : go together; "the colors don't harmonize"; "their ideas
         concorded" syn: harmonize, harmonise, consort, accord,
          concord, agree
see also:
harmonize harmonise consort accord concord agree 

[2] : Moby Thesaurus II by Grady Ward, 1.0

30 moby thesaurus words for "fit in":
   accord, be there, belong, conform, correspond, dovetail,
   fall in with, fall into line, fit, follow the crowd,
   follow the fashion, follow the rule, get in line, go,
   go through channels, harmonize, have its place, have place,
   implant, infix, inlay, jibe, keep in step, pass muster,
   play the game, square, stay in line, tally, tessellate,
   toe the mark

Fit >> F Words
Fit, definition of term: Fit
fit_pag1.html

Fit To >> F Words
Fit To, definition of term: Fit To
fit+to_pag1.html

Fit In >> F Words
Fit In, definition of term: Fit In
fit+in_pag1.html