'Survival of the fittest' definitions:

Definition of 'survival of the fittest'

From: WordNet
noun
A natural process resulting in the evolution of organisms best adapted to the environment [syn: survival, survival of the fittest, natural selection, selection]

Definition of 'Survival of the fittest'

From: GCIDE
  • Survival \Sur*viv"al\, n. [From Survive.]
  • 1. A living or continuing longer than, or beyond the existence of, another person, thing, or event; an outliving. [1913 Webster]
  • 2. (Arhaeol. & Ethnol.) Any habit, usage, or belief, remaining from ancient times, the origin of which is often unknown, or imperfectly known. [1913 Webster]
  • The close bearing of the doctrine of survival on the study of manners and customs. --Tylor. [1913 Webster]
  • Survival of the fittest. (Biol.) See Natural selection, under Natural. [1913 Webster] Survivance