'lipoid' originates from New Latin and Ancient Greek, specifically the New Latin word 'lipoides', where Greek 'lipos' meant 'fat' and Greek suffix '-oeidēs' (from 'eidos') meant 'form, resembling'.

'lipoid' developed in scientific usage in the 19th century (via New Latin 'lipoides' and French 'lipoïde') and entered modern English medical and biochemical vocabulary as 'lipoid'.

Initially it meant 'resembling fat' (i.e., 'fat-like'); over time it retained this basic sense and has been used both adjectivally and as a noun for fatlike substances.