lick. 1. to pass the tongue over the surface of, as to moisten, taste, or eat (often fol. by up, off, from, etc.): to lick a postage stamp; to lick an ice-cream cone. 2. to make, or cause to become, by stroking with the tongue: to lick a spoon clean. 3. (of waves, flames, etc.) to pass or play lightly over. 4. Informal.