'hypertonic' originates from New Latin 'hypertonicus', ultimately from Greek elements 'hyper-' and 'tonos', where 'hyper-' meant 'over, beyond' and 'tonos' meant 'tension' or 'stretching'.

'hypertonic' changed from the New Latin medical term 'hypertonicus' (formed from Greek roots) and was adopted into English medical usage in the 19th century as 'hypertonic'.

Initially used with senses related to excess tension (e.g., increased muscle tone), it has come to be widely used for the specific modern sense 'having higher osmotic pressure' as applied to solutions; both senses (osmotic and muscular tension) coexist in medical contexts.