'spasmolytic' originates from Modern Latin/Greek-influenced formation, specifically from Greek 'spasmos' meaning 'a convulsion, spasm' and Greek-derived combining form '-lytic' (from Greek 'lytikos'/'lyein') meaning 'able to loosen or dissolve'.

'spasmolytic' was formed in New/Modern Latin as 'spasmolyticus' (or similar formations) from Greek elements 'spasmos' + 'lytikos' and was borrowed into English in its current form 'spasmolytic' (with plural 'spasmolytics').

Initially it literally meant 'able to loosen or dissolve a spasm' (a substance that counteracts a spasm); over time it has been used specifically to denote drugs or agents that relieve or prevent muscle spasms.