uočiti

1. to notice; to spot
   Uočio sam je u gužvi ispred bioskopa. — I spotted her in the crowd outside the cinema.
   Niko nije uočio grešku u tekstu. — Nobody noticed the mistake in the text.
2. (of a problem, difference) to identify; to recognize
   Stručnjaci su uočili ozbiljan problem u sistemu. — Experts identified a serious problem in the system.

Slightly more formal than primetiti; the imperfective is uočavati.