Definitions for "Drop in"
The most henious crime in surfing. Surfing is based on a system of priorities with the surfer closest to the peak, or where the wave is breaking having priority. A drop in is where another surfer catches the same wave disregarding the other surfers priority
Taking off on a wave that is already being ridden by another surfer. Contrary to good etiquette.
When a skater or rider begins his run
Keywords:  halfpipe, riding
Riding into the halfpipe.
When a sink is mounted within the surface of a countertop such that the rim of the sink is visible above the countertop, it is called a “drop-in” sink. When a sink has been mounted from underneath the cabinet such that the rim is not visible, it is referred to as an “undermount” sink.
Keywords:  ramp, obstacle, enter, top
To enter the ramp or obstacle from the top.
Keywords:  cam, lever, gate, corresponding, dial
n. the gate area of the drive cam where the lever nose drops into. Usually identified with a corresponding number on the dial
Keywords:  ahead, you'll, friend, verb, miss
(verb) To turn onto to a little used single track. Best,if you don't know the way, to let your friend drop in ahead of you, or you'll miss the turn.
visit informally and spontaneously; "We frequently drop by the neighbors' house for a cup of coffee"
Keywords:  punch, see
See ‘Punch in’.