fill out phr v 1 [T fill sth ↔ out] to write information in special spaces on a printed piece of paper 填写〔表格〕: You'll have to fill out a membership form before you can use the gym. 使用健身房之前，你必须填写一张会员登记表。 2 [I] to get fatter 变胖: Her face is beginning to fill out. 她的脸开始变圆了。