Entry 1 sense Webster, 1913 Metrology · Me·trol·o·gy · IPA /mɛˈtɹɑ.lə.d͡ʒi/ 01 n. The science of, or a system of, weights and measures; also, a treatise on the subject. 1. The science of, or a system of, weights and measures; also, a treatise on the subject.