'atheromatous' originates from New Latin/modern medical English, specifically from the noun 'atheroma' plus the adjectival suffix '-ous', where 'atheroma' ultimately comes from Greek 'athēroma' meaning 'gruel' or 'porridge'.

'atheromatous' developed from the New Latin word 'atheroma' (from Greek 'athēroma'); the adjective was formed in English by adding the suffix '-ous' to describe tissues 'having or producing atheroma', becoming established in medical usage in the 19th century.

Initially the Greek term described a 'gruel-like' deposit; over time it came to denote fatty or lipid deposits (atheroma) in arterial walls, and 'atheromatous' came to mean 'relating to or characterized by such arterial plaques'.