'osmotolerant' originates from a combination of Greek and Latin elements: Greek 'osmos' (from Greek ὠσμός) meaning 'push' or 'impulse' (used in the formation of 'osmosis'), and Latin 'tolerans' (from 'tolerare') meaning 'to bear' or 'to endure'.

'osmos' entered scientific English via the noun 'osmosis' in the early 19th century; 'tolerant' comes from Latin 'tolerare' through Old French/Middle English; the compound 'osmotolerant' is a modern scientific formation combining the prefix 'osmo-' with the adjective 'tolerant', established in 20th-century biological literature to describe organisms that withstand osmotic stress.

Individually, 'osmos' originally referred to a physical 'push' and 'tolerant' to 'able to bear'; together the coined term 'osmotolerant' came to mean 'able to survive or grow under osmotic stress (high or variable solute concentration)'.