*fast² adv 1 moving or happening quickly 快，迅速: Stop driving so fast! 别把车开得那么快！ You're learning fast. 你学得很快。 2 fast asleep completely asleep 熟睡的 3 firmly or tightly 紧紧地; 牢牢地: be stuck fast The boat's stuck fast in the mud. 小船死死地陷在泥里。 hold sb/sth fast Rudi began to fall, but the rope held him fast. 鲁迪开始往下坠，但那根绳子将他紧紧拉住。