toothful adjective 2noun 1forms 3 adjective2 •Toothy; showing the teeth. •(no longer used) Toothsome. noun1 •(no longer used) A small amount, especially a small alcoholic drink.The signal officer was looking wise over something that boomed and buzzed alternately; the machine-gun officer may, or may not, have been enjoying another toothful. — 1917 formstoothfuls · more toothful · most toothful