incapable of being surmounted, passed over, or overcome; insuperable: an insurmountable obstacle.

What does it mean when someone is insurmountable?

: incapable of being surmounted : insuperable insurmountable problems.

What is the root of the word insurmountable?

insurmountable (adj.)

1690s, from in- (1) "not, opposite of" + surmountable. Related: Insurmountably. Brachet calls French insurmontable a "ghastly philological monster."