'atherosclerotic' originates from Greek, specifically from the combining form 'athēra' (meaning 'gruel, porridge' used metaphorically for fatty deposit) and 'sklēros' (meaning 'hard'), with the adjectival suffix '-tic'.

'atherosclerotic' developed from the medical noun 'atherosclerosis' (from New Latin/Modern medical formation combining Greek elements 'athēra-' + 'sclerosis') and was formed in English as the adjective describing tissues affected by that condition.

Initially it referred specifically to the pathological process of 'hardening caused by fatty deposits'; over time it has been used adjectivally to describe arteries or tissues that are diseased by that process.