Adjective on the button has 1 sense
  1. on the nose, on the button - being precisely to a prescribed or specified criterion; "his guess was on the nose"; "the prediction for snow was right on the button"
    Antonym: imprecise (indirect, via precise)
,Adverbial on the button has 1 sense
  1. precisely, exactly, on the nose, on the dot, on the button - just as it should be; "`Precisely, my lord,' he said"
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