unexpected

As a verb mismatch

is to match unsuitably; to fail to match.

As a noun mismatch

is something that does not match; something dissimilar, inappropriate or unsuitable.

As an adjective unexpected is

not expected, anticipated or foreseen.

As adjectives the difference between incredible and unexpected

is that incredible is incredible while unexpected is not expected, anticipated or foreseen.

Irregular is a synonym of unexpected.

As adjectives the difference between irregular and unexpected

is that irregular is irregular while unexpected is not expected, anticipated or foreseen.

Unexpected is a related term of broken.

As an adjective unexpected

is not expected, anticipated or foreseen.

As a proper noun broken is

(derogatory|slang) torres strait creole.

Unexpected is a related term of rugged.

As adjectives the difference between unexpected and rugged

is that unexpected is not expected, anticipated or foreseen while rugged is broken into sharp or irregular points; uneven; not smooth; rough or rugged can be having a rug or rugs.

As a verb rugged is

(rug).

As a noun remain

is state of remaining; stay.

As a verb remain

is to stay behind while others withdraw; to be left after others have been removed or destroyed; to be left after a number or quantity has been subtracted or cut off; to be left as not included or comprised.

As an adjective unexpected is

not expected, anticipated or foreseen.

As adjectives the difference between unexpected and spontaneous

is that unexpected is not expected, anticipated or foreseen while spontaneous is self-generated; happening without any apparent external cause.

As adjectives the difference between unprecedented and unexpected

is that unprecedented is never before seen or done, without precedent while unexpected is not expected, anticipated or foreseen.

As adjectives the difference between unintended and unexpected

is that unintended is not intended; unplanned while unexpected is not expected, anticipated or foreseen.

As adjectives the difference between unfamiliar and unexpected

is that unfamiliar is strange, not familiar while unexpected is not expected, anticipated or foreseen.

As a noun unfamiliar

is an unfamiliar person; a stranger.