unmanneristic Share definition Flag Unmanneristic is when someone is being a little bit annoying at the dinner table and you want to call them out on it. “Gosh stop being so unmanneristic” she said to her son. unmanneristic by Poopnugget113 February 3, 2018 0 0 Get merch Get the unmanneristic mug. Buy Now — $32.95 See more merch