die

Concise Oxford English Dictionary © 2008 Oxford University Press:
die1

▶verb (dies, dying, died)

• 1 stop living.

  ■ (die out) become extinct.

  ■ be forgotten.

• 2 (often die away/down) become less loud or strong.

• 3 informal used to emphasize strong desire, embarrassment, shock, etc.: I nearly died when I saw them.

  ■ (be dying for/to do something) be very eager for something.

– phrases
die a (or the) death Brit. fail utterly or come to an end.
die hard change very slowly: old habits die hard.
never say die said to encourage someone not to give up hope.
to die for informal extremely good or desirable.

– origin ME: from ON deyja, of Gmc origin; rel. to dead.

Concise Oxford English Dictionary © 2008 Oxford University Press:
die2

▶noun

• 1 singular form of dice.

• 2 (pl. dies) a device for cutting or moulding metal or for stamping a design on coins or medals.

• 3 (pl. dies) Architecture the cubic part of a pedestal between the base and the cornice; a dado or plinth.

– phrases
the die is cast a decision has been taken that cannot be changed.
(as) straight as a die

• 1 completely straight.

• 2 entirely open and honest.

– origin ME: from OFr. de, from L. datum ‘something given or played’, neut. past part. of dare.

usage: In modern standard English, the singular die (rather than dice) for sense 1 is relatively uncommon. Dice is widely used for both the singular and the plural.