English Dictionary

nail down

verb

(transitive) to attach with nails / (idiomatic, transitive) to make something (e.g. a decision or plan) firm or certain

He used a hammer to nail down the loose board.

意味（1）

(transitive) to attach with nails

Nail down the shelf, then paint it.

意味（2）

(idiomatic, transitive) to make something (e.g. a decision or plan) firm or certain

They haven't nailed down their vacation plans yet.