/neɪl ||; nel/noun[C] 1 the thin hard layer that covers the ends of your fingers and toes 指甲；趾甲: fingernails/toenails 手指甲；趾甲 ☞picture at body 见body插图
2 a small thin piece of metal that is used for holding pieces of wood together, hanging pictures on, etc 钉；钉子:
to hammer in a nail 用锤子把钉子敲进去 ☞pictures at bolt and tool 见bolt及tool插图
nail verb [T]
hit the nail on the head→
HIT¹
nail sb down (to sth) to make a person say clearly what he/she wants or intends to do 使某人明确说出想要什么或打算做什么:
She says she'll visit us in the summer but I can't nail her down to a definite date. 她说她将会在夏天探望我们，但我无法使她明确说定日期。