multiply/ˋmʌltə͵plaI; ˈmʌltəplaI or ˈmʌltIplaI/v [I,T] multiplied , multiplying , multiplies 1 to do a calculation in which you add one number to itself a particular number of times [→ divide] 乘﹐乘以: multiply sth by sth Four multiplied by five is 20. 4 乘以 5 等于 20。see box at见 CALCULATE 方框2 to increase by a large amount or number, or to make something do this (使)大大增加﹐(使)成倍增加: Smoking multiplies the risk of having a heart attack. 吸烟会大大增加心脏病发作的风险。