3do noun
plural dos [count] informal 1 : something that a person should do — usually used in the phrase dos and don'ts ▪ She told her daughter about the dos and don'ts of dating. [=about the things that she should and should not do when dating someone] 2 US : a way of cutting and arranging a person's hair : hairdo
▪ She was worried that the wind might mess up her do. 3 : a party or social gathering
▪ We threw a big do for her after graduation.
▪ She was worried that the wind might mess up her do.
▪ We threw a big do for her after graduation.
— compare 4do
