'arsenopyrite' is formed from the combining form 'arseno-' (from 'arsenic') and 'pyrite' (from Greek 'pyr' meaning 'fire'); 'arsenic' ultimately comes from Greek 'arsenikon' and 'pyrite' from Greek 'pyr'.

'arsenic' derives from Greek 'arsenikon' (via Medieval Latin/French), and 'pyrite' comes from Greek 'pyr' ('fire') through Latin and Old French; the compound 'arsenopyrite' was coined in modern mineralogy to denote the arsenic-bearing pyrite-like mineral and entered scientific usage in the 19th century.

Initially the elements/components named ('arsenic' and 'pyrite') had broader classical meanings, but combined in modern mineralogical usage the term specifically denotes the iron arsenic sulfide mineral (FeAsS).