Yes, "-logue" is a suffix, though it comes from the Greek "-logos" (meaning "speech" or "discourse"). It appears in words like: * Dialogue (conversation between two or more people) * Monologue (a long speech by one person) * Catalogue (a list with descriptions) In American English, some words drop the "-ue" (e.g., "catalog" instead of "catalogue").

It's described as a 'noun combining form' in Oxford and Merriam-Webster. This is from Merriam-Webster. -logue noun combining form variants or -log 1 : discourse : talk duologue 2 : student : specialist sinologue Etymology French -logue, from Latin -logus, from Greek -logos, from legein to speak