oklevati

1. to hesitate; to waver
   Nemoj da oklevaš, javi joj se odmah. — Don't hesitate, get in touch with her right away.
   Dugo je oklevao pre nego što je prihvatio posao. — He hesitated for a long time before accepting the job.

Common in bez oklevanja "without hesitation"; the action follows with da + present or sa + instrumental.