'malleolar' originates from Latin, specifically the word 'malleolus', where 'malleolus' is a diminutive of 'malleus' meaning 'hammer' and the English/Latin adjectival ending '-ar' (via New Latin) means 'pertaining to'.

'malleolar' changed from New Latin/Medieval Latin forms such as 'malleolaris' derived from Latin 'malleolus' and entered modern medical English as 'malleolar' to describe things relating to the malleolus.

Initially it referred (via 'malleolus') to a 'little hammer' (literal sense); over time the term came to denote the bony protuberances at the ankle and things related to them, evolving into the current sense 'relating to the malleolus (ankle)'.