Merriam-Webster's Word of the Day for August 17, 2026, is lackadaisical. Lackadaisical is an adjective describing someone or something as lacking interest, enthusiasm, or zest. An example illustrates this by mentioning feeling lackadaisical in the summer heat and lazily tossing a ball. Another example uses lackadaisical to describe a poor performance in a sports game. The origin of the word connects to expressions of sorrow and disappointment. Historically, people would cry "Lackaday!" to express their unhappiness. This phrase was a shortened form of "alack the day," where "alack" denoted sorrow or regret. By the mid-1700s, the adjective lackadaisical emerged from this expression. It was used to describe weary and exasperated individuals and their listless actions. Currently, lackadaisical primarily signifies languidness and laziness.