'nonhemangiomatous' is formed in modern English by the negative prefix 'non-' + 'hemangiomatous'. 'Hemangiomatous' comes from 'hemangioma' with the adjectival suffix '-ous'. 'Hemangioma' itself combines Greek elements 'haima' (blood) + 'angeion' (vessel) with the tumor-forming suffix '-oma'.

'hemangioma' entered medical New Latin from Greek roots ('haima' + 'angeion') and was adopted into English medical usage; the adjective 'hemangiomatous' was then formed from 'hemangioma', and 'non-' was later prefixed in English to form 'nonhemangiomatous'.

Originally, 'hemangioma' referred specifically to a blood-vessel tumor; over time derived forms like 'hemangiomatous' came to describe tissue having features of such tumors, and 'nonhemangiomatous' now denotes absence of those features.