'speciesist' originates from English, formed by combining the noun 'species' (from Latin 'species' meaning 'appearance, kind') with the suffix '-ist' (a noun-forming suffix meaning 'one who practices or is concerned with').

'speciesist' is a modern coinage first recorded in the 20th century; the term was coined and used in animal‑welfare and animal‑rights discourse in the 1970s (often credited to psychologist Richard D. Ryder) and was popularized by writers such as Peter Singer in the 1975 book 'Animal Liberation.' The Latin 'species' entered English via scientific and legal usage from Medieval Latin.

When coined, it specifically meant 'one who discriminates against or assigns lesser moral status to beings of other species'; over time it has retained that core meaning and is now a standard term in discussions of animal ethics.