top out verb 4top-out noun 1forms 4 verb4 •To reach one's highest point.With her 390 V-8 spinning at redline, she tops out at 130 miles per hour. •To complete the construction of a tall building, originally by putting on a "topping-out" course. •To complete a route by reaching and climbing over its top. •To quit one's career during a period of success. top-out noun1 •The act of topping out, reaching the top of a route. formstopped out · topping out · tops out · top-outs