'cephaloid' originates from Modern English formation using Greek roots: Greek 'kephalē' meaning 'head' plus the suffix '-oid' from Greek 'eidos' meaning 'form' or 'likeness'.

'kephalē' (Greek) passed into Late Latin/New Latin as 'cephal-' (forming elements such as 'cephalo-'), and in Modern English these combining forms produced coinages like 'cephaloid' in scientific usage.

Initially based on the Greek root meaning 'head', the term evolved in scientific contexts to mean 'headlike' or 'having the form of a head' and retains that descriptive sense in modern usage.