'anthracoid' originates from New Latin (or formation in modern scientific English), ultimately from Greek 'anthrax' where 'anthrax' meant 'coal', combined with the suffix '-oid' meaning 'like' or 'resembling'.

'anthracoid' was formed by combining Greek 'anthrax' (ἄνθραξ) with the suffix '-oid' (from Greek '-oeidēs' meaning 'form, likeness') via New Latin/scientific coinage and entered technical English usage to mean 'coal-like' or 'anthrax-like'.

Initially formed to convey the sense 'coal-like' (from 'anthrax' = 'coal'), its use in medical or scientific contexts also allowed a secondary sense of 'anthrax-like' (relating to the disease), so the modern senses cover both coal-like and anthrax-related meanings.