izmak

1. (of time, usually na izmaku) end; close
   Leto je polako na izmaku. — Summer is slowly drawing to a close.
   Na izmaku godine svi su umorni. — At the end of the year everyone is tired.
2. (of strength, supplies, na izmaku) running out
   Strpljenje mi je na izmaku. — My patience is running out.
   Posle šest sati hoda snage su nam bile na izmaku. — After six hours of walking our strength was almost gone.

Almost always used in the phrase "na izmaku".