'pH-tolerant' is a modern compound formed from the scientific abbreviation 'pH' and the adjective 'tolerant'. 'pH' was coined by Danish chemist Søren P. L. Sørensen in 1909, where 'p' stood for German 'potenz' meaning 'power' and 'H' stood for 'hydrogen'. 'Tolerant' originates from Latin 'tolerare' meaning 'to bear.'

'pH' entered scientific English in the early 20th century and was later used as a prefix in compound adjectives (e.g. 'pH-neutral', 'pH-tolerant'). 'Tolerant' came into English via Old French/Late Latin (Old French 'tolerant', from Late Latin 'tolerantem') and evolved into the modern adjective 'tolerant'.

The component 'tolerant' originally meant 'able to bear or endure' (in a general sense); in the compound 'pH-tolerant' the meaning has specialized to 'able to endure differences in acidity/alkalinity (pH)'.