posuđivati

1. (to someone) to lend
   Ne volim da posuđujem knjige, nikad mi ih ne vrate. — I don't like lending books, people never give them back.
2. (od + gen.) to borrow
   Stalno posuđuje novac od roditelja. — He keeps borrowing money from his parents.
   Srpski je vekovima posuđivao reči iz turskog. — Serbian borrowed words from Turkish for centuries.

In Serbia pozajmljivati is more common; 'borrow' is usually marked by od + gen.