expression, i-adjective
unexpected; unforeseen; contrary to expectations
Emphasizes that something was completely beyond what one imagined or anticipated. Often used when an event or outcome is surprising in a way that defies prior thought. Similar to 思いがけない, but with a stronger nuance of 'not even having crossed one's mind'.
See also: 思いがけない
思いもかけない場所で旧友に会った。
I ran into an old friend in a completely unexpected place.
The news that he would resign was totally unforeseen.
Both mean 'unexpected', but 思いもかけない carries a stronger sense of 'not even having imagined it', while 思いがけない is more general and common.
Phrase composed of 思い (thought) + も (even) + かけない (negative of 掛ける, here meaning 'to have in mind'). Literally 'not even thought of'.