'auxotonic' is formed from the combining form 'auxo-' from Greek 'auxein' meaning 'to increase, grow' and the Greek-derived suffix '-tonic' from 'tonos' meaning 'tension, stretch'.

'auxo-' (Greek 'auxein') and '-tonic' (Greek 'tonos') were combined in modern scientific coinage (Neo-Latin/Modern English) to form 'auxotonic' to describe a contraction with changing tension; the term appears in physiological literature in the late 19th to 20th century.

Originally built from elements meaning 'increasing tension,' the term has come to denote specifically a contraction type where both tension and length change simultaneously rather than simply an increase in tension.