The word 'squishy' is a relatively modern English formation, built upon the imitative verb 'squish', which emerged in the 17th century to mimic the sound of soft impact or compression. The core 'squ-' sound cluster is common in English words implying wet, soft, or crushing actions (e.g., squash, squeeze). By adding the productive adjectival suffix '-y', the word transforms the action into a descriptive state, literally meaning "having the qualities of something that squishes". This etymological logic perfectly maps to its modern meanings, describing either a physical texture that yields with a soft, wet sound or, metaphorically, ideas that lack firmness and are easily shaped or dismissed.

Structure: squish (to crush or squeeze softly) + y (adjective-forming suffix) - squish: An English onomatopoeic root, imitative of the sound or action of something soft being crushed. - y: A native English suffix (from Old English -ig, Proto-Germanic -īgaz, Proto-Indo-European -kos) used to form adjectives meaning "characterized by; full of; having the quality of".