The term 'ADD LIQUOR TO' can be summarized by two crossword solutions: LACE (4 letters) and SPIKE (5 letters). LACE is a verb meaning to add a small amount of an alcoholic beverage to a non-alcoholic drink, such as adding a splash of rum to a glass of orange juice. SPIKE is a verb meaning to add a large amount of an alcoholic beverage to a non-alcoholic drink, such as adding a shot of vodka to a glass of lemonade. Both terms refer to the act of adding liquor to a non-alcoholic drink.