Etymology: < French -logue < classical Latin -logus < ancient Greek -λογος < λόγος word, speech, discourse (see Logos n.).Ancient Greek -λογος forms compounds denoting both people (see sense 1) and types of discourse (see sense Compounds). Attested from Middle English in both senses; first attested in loans < Greek, via Latin and French, as astrologue , theologue (sense 1), and catalogue , decalogue , dialogue , prologue (sense 2). Productive in English from the late 16th cent. Decalogue gave rise to ennealogue , hecatologue , pentalogue , while dialogue gave rise to tetralogue and trialogue ; compare quadrilogue , < French. Originally combining with first elements of Greek origin, but note modern formations as tziganologue , and the blends travelogue , vinylogue . Now little used in sense 1, derivatives in -loger, -logist, or -logian being commonly preferred.
This entry has not yet been fully updated (first published 1903; most recently modified version published online December 2018).