So difficult or large that it cannot be overcome, defeated, or solved.
From prefix 'in-' (not) plus 'surmountable' (able to be overcome), from French 'surmonter' (to overcome), combining 'sur' (over) and 'monter' (to mount/climb).
Psychologists note that what seems 'insurmountable' is often just about perspective—mountains that look impossible from the base look manageable once you start climbing, showing the word describes our fear more than reality.
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