WordNet sense 1 (a crushing remark):

put-down, squelcher, takedown

WordNet sense 2 (an electric circuit that cuts off a receiver when the signal becomes weaker than the noise):

squelch circuit

WordNet sense 3 (walk through mud or mire):

slop, slosh, splash, squish, splosh

WordNet sense 4 (to compress with violence, out of natural shape or condition):

crush, mash, squash, squeeze

WordNet sense 5 (suppress or crush completely):

quell, quench