The word 'squeamish' entered English in the late Middle English period from the Anglo-French term 'escoymous'. While its ultimate roots are obscure and debated, it is thought to be connected to the Old French verb 'escoimier', which conveyed the sense of flinching or shrinking back. This core idea of physical and mental recoil evolved seamlessly into the modern meanings. The journey from a term describing a physical reflex to one describing a sensitive disposition—whether to grossness or to moral slight—illustrates a classic semantic broadening, where an internal feeling of aversion became its defining characteristic.

The word is a simplex form. Its origin is Anglo-French 'escoymous', of uncertain ultimate origin, possibly related to Old French 'escoimier' meaning to flinch or recoil.