poništavati

1. to annul; to cancel; to revoke
   Sud često poništava takve ugovore. — The court often annuls such contracts.
   Komisija poništava glasanje na nekim mestima. — The commission is annulling the vote at some polling stations.
2. (of a ticket) to validate; to punch
   Putnici poništavaju karte čim uđu u autobus. — Passengers validate their tickets as soon as they board the bus.
3. (poništavati se) to cancel out; to negate
   Ove dve sile se međusobno poništavaju. — These two forces cancel each other out.