stareti

1. to grow old; to age
   Svi starimo, to je normalno. — We're all getting older, that's normal.
   Roditelji mi polako stare. — My parents are slowly getting old.
2. (of things, ideas) to date; to become outdated
   Tehnologija danas veoma brzo stari. — Technology becomes outdated very quickly these days.
   Dobra muzika nikad ne stari. — Good music never gets old.

The perfective is ostariti.