\Ter`mi*nol"o*gy\, n. [L. terminus term + -logy: cf. F. terminologie.] 1. The doctrine of terms; a theory of terms or appellations; a treatise on terms. 2. The terms actually used in any business, art, science, or the like; nomenclature; technical terms; as, the terminology of chemistry. The barbarous effect produced by a German structure of sentence, and a terminology altogether new. --De Quincey.