Terminology
early 19th century: from German Terminologie, from medieval Latin terminus ‘term’.
wiktionary
From Latin terminus(“a term”) + -ology(“study of”), from -o-(“( interconsonantal)”) + -logy, from Ancient Greek -λογία(-logía, “-logy, branch of study, to speak”)
etymonline
terminology (n.)
1770, from German Terminologie, a hybrid coined by Christian Gottfried Schütz (1747-1832), professor of poetry and rhetoric at Jena, from Medieval Latin terminus "word, expression" (see terminus) + Greek -logia "a dealing with, a speaking of" (see -logy). Related: Terminological.
Decandolle and others use the term Glossology instead of Terminology, to avoid the blemish of a word compounded of two parts taken from different languages. The convenience of treating the termination ology (and a few other parts of compounds) as not restricted to Greek combinations, is so great, that I shall venture, in these cases, to disregard this philological scruple. [William Whewell, "The Philosophy of the Inductive Sciences," 1847]