'antimonium' originates from Medieval Latin, specifically the word 'antimonium', where the formation was influenced by Old French 'antimoine' and elements interpreted (folk‑etymologically) as 'anti-' meaning 'against' and Greek 'monos' meaning 'alone' (the true root is uncertain).

'antimonium' passed into Old French as 'antimoine' and then into Middle English as 'antimony'; the Latin form 'antimonium' continued to be used in scholarly, medical, and pharmacopeial Latin.

Initially it referred to the mineral/compound used in medicine and metallurgy; over time the sense broadened and stabilized as the name of the chemical element now called 'antimony'.