means The act of fastening something shut with a lock, or in dance, a funk style where you suddenly freeze a movement and hold the pose before snapping back into motion.

from From 'lock,' an Old English word ('loc') for a fastening or enclosure, with deep Germanic roots tied to the idea of closing or shutting. The dance sense is a 1970s American coinage: dancer Don Campbell gave it the name when his abrupt, held-still moves looked like the body had 'locked' in place — a literal freezing of the funk.