Synonyms of uncongenial

2 Syllables
unfit
3 Syllables
mismatched, unstirred, incongruous, discourteous, unfriendly, asocial, uncivil, unpitying, unpleasant, discordant
4 Syllables
ill-equipped, disagreeable, inharmonious, ungregarious, unadapted, aversive, unsociable, unwelcoming, disobliging, unneighborly, unmusical
5 Syllables
unsympathetic, unreceptive, inhospitable, incompatible, inconformable
6 Syllables
uncompassionate