The definition of insurmountable is something that is too difficult or too great to overcome.
An example of something that would be described as insurmountable is an obstacle for which there truly is no way to get around.
not surmountable; that cannot be passed over or overcome; insuperable
Impossible to surmount; insuperable: insurmountable difficulties.
- in′sur·mount′a·bil′i·ty, in′sur·mount′a·ble·ness
(comparative more insurmountable, superlative most insurmountable)
- in- + surmountable