trzati

1. (trzati se) to flinch; to twitch; to jerk
   Trza se na svaki zvuk iz hodnika. — He flinches at every sound from the hallway.
   Beba se trza u snu. — The baby twitches in its sleep.
2. (of weapons) to recoil; to kick
   Ova puška jako trza. — This rifle kicks hard.
3. colloq. (trzati na + acc.) to fall for; to have a thing for
   Ona baš trza na muškarce s bradom. — She really has a thing for men with beards.
4. (of strings, ropes) to jerk; to pluck
   Nervozno je trzao žice gitare. — He was nervously plucking the guitar strings.

The sense "flinch" takes se: trzati se. For a weapon's recoil it is usually used without se: Puška trza.