n. & v.
n. 1 (in lawn tennis, squash, etc.) an obstruction of a ball or a player in certain ways, requiring the ball to be served again. 2 (archaic except in without let or hindrance) obstruction, hindrance.
v.tr. (letting; past and past part. letted or let) archaic hinder, obstruct.
[ OE lettan f. Gmc, rel. to LATE ]