1640s, probably a variant of squash (v.), perhaps by influence of obsolete squiss "to squeeze or crush" (1550s). Related: Squished; squishing.
Entries linking to squish
squash v.
"to crush, squeeze," early 14c., squachen, from Old French esquasser, escasser "to crush, shatter, destroy, break," from Vulgar Latin *exquassare, from Latin ex "out" (see ex-) + quassare "to shatter" (see quash "to crush"). Related: Squashed; squashing.
squishy adj.
1847, from squish + -y (2). Related: Squishily; squishiness.