okomit

1. vertical; sheer
   Penjali su se uz okomitu stenu. — They were climbing a sheer rock face.
   Nacrtaj okomitu liniju na sredini papira. — Draw a vertical line in the middle of the paper.
2. (in geometry, + na) perpendicular
   Ova prava je okomita na osnovicu trougla. — This line is perpendicular to the base of the triangle.

Meaning 'perpendicular' it takes na + acc.: okomit na pravu.