Affixes

Many examples exist, of which a few are archaeologist, biologist, entomologist, futurologist, geologist, meteorologist, ornithologist, pathologist, psychologist, technologist, and zoologist. The form is actively used to make new words as required.

At one time, the form ‑loger with the same sense was common (see ‑er¹), but most examples have been replaced by others in ‑logist. A rare surviving example is astrologer.