The verb 'squash' entered English in the mid-16th century, derived from the Old French verb 'esquasser', meaning to crush or smash. This French term itself originated from the Vulgar Latin 'exquassare', a compound of the intensive prefix 'ex-' and 'quassare', meaning to shake or shatter. The original Latin 'quassare' is a frequentative form of 'quatere', to shake, a verb with Proto-Indo-European roots. The modern meanings of pressing flat and forcing into a confined space flow directly from this core sense of violent compression. The name for the sport, first recorded in the early 19th century, comes from the soft, crushable ball used, in contrast to the harder ball used in the related game of rackets. The vegetable name, recorded from the mid-17th century, is a shortened form of the Narragansett (Algonquian) word 'askútasquash', literally meaning 'the green things that may be eaten raw', borrowed by English colonists in North America.

This word is a simplex loanword. Its core form is not productively built from separable morphemes in modern English.