on the button

Từ điển WordNet v3.1 - WordNet Dictionary

I - adjective

being precise with regard to a prescribed or specified criterion
- his guess was on the nose
- the prediction for snow was right on the button
• Syn:
on the nose
• Similar to:
precise

II - adverb

just as it should be
- 'Precisely, my lord,' he said
• Syn:
precisely, exactly, on the nose, on the dot