'alcahest' originates from New Latin, specifically the word 'alchahestum', where 'al-' was a common prefix in alchemical terms and 'chahest' is of unknown origin.

'alchahestum' transformed into the modern English word 'alcahest' through Middle English.

Initially, it meant 'a universal solvent in alchemy', and this meaning has largely remained the same in modern usage.