segnuti

1. (+ za + instr. or u + acc.) to reach for; to reach into
   Segnuo je u džep i izvadio ključeve. — He reached into his pocket and took out the keys.
   Lopov je segao za pištoljem. — The thief reached for his gun.
2. (+ do + gen.) to reach; to come up to
   Voda mu je segla do kolena. — The water came up to his knees.

For 'to reach for something', posegnuti za + instrumental is more common.