Entry 1 sense Webster, 1913 Undying /ən-dī'-ĭng/ · Un·dy·ing · IPA /əndˈaɪɪŋ/ 01 a. Not dying; imperishable; unending; immortal; as, the undying souls of men. 1. Not dying; imperishable; unending; immortal; as, the undying souls of men.