Expire while working; keep working to the end; die in active service rather than in retirement. Also 'die in harness.'
Examples:
- He'll never retire—he'll die with his boots on.
- She knows she'll never get promoted, but she wants to die in harness.
Origin: Probably alludes to soldiers dying on active duty; Shakespeare used 'harness' in the sense of armor in Macbeth.
Synonyms: die in harness