Definition of screw back in US English:

screw back

noun

  • Spin imparted to the cue ball by a player in striking it with the cue below the centre, causing it to move backwards after hitting the object ball.

Origin

Mid 19th century; earliest use found in John Roberts (1823–1893). From screw + back, after to screw back.

Pronunciation

screw back

/ˈskruː bak/