'antispasmodic' originates from Greek elements: the prefix 'anti-' (Greek 'antí-', meaning 'against') combined with 'spasmodic', derived from Greek 'spasmos' meaning 'a convulsion or spasm'.

'spasmos' (Greek) became Latin 'spasmus' and Medieval/Modern Latin/French forms (e.g. 'spasmodicus'), and in English the prefix 'anti-' was attached in modern usage to form 'antispasmodic' (attested from the 18th–19th century).

Initially it referred to substances or measures 'against spasms'; over time the term has remained specialized but broadened to denote any drug or agent that relieves or prevents various types of muscle spasms.