unsurmountable

verb (used with object)

1. to mount upon; get on the top of; mount upon and cross over: to surmount a hill.
2. to get over or across (barriers, obstacles, etc.).
3. to prevail over: to surmount tremendous difficulties.
4. to be on top of or above: a statue surmounting a pillar.
5. to furnish with something placed on top or above: to surmount a tower with a spire.
6. Obsolete.
   1. to surpass in excellence.
   2. to exceed in amount.

adjective

1. (of a problem, etc) not capable of being solved or overcome

verb (tr)

1. to prevail over; overcometo surmount tremendous difficulties
2. to ascend and cross to the opposite side of
3. to lie on top of or rise above
4. to put something on top of or above
5. obsolete to surpass or exceed

adj.1701, from un- (1) “not” + surmountable (see surmount). v.late 14c., “to rise above, go beyond,” from Old French surmounter “rise above,” from sur- “beyond” (see sur-) + monter “to go up” (see mount (v.)). Meaning “to prevail over, overcome” is recorded from late 14c. Related: Surmounted; surmounting.