'never-say-die' definitions:

Definition of 'never-say-die'

From: WordNet
adjective
Impossible to subdue [syn: indomitable, never-say- die, unsubduable]

Definition of 'never-say-die'

From: GCIDE
  • never-say-die \never-say-die\ adj. Incapable of being subdued.
  • Syn: indomitable, unsubduable. [WordNet 1.5]