'throwback' definitions:

Definition of 'throwback'

From: WordNet
adjective
Characteristic of an atavist [syn: atavistic, throwback(a)]
noun
An organism that has the characteristics of a more primitive type of that organism [syn: atavist, throwback]
noun
A reappearance of an earlier characteristic [syn: atavism, reversion, throwback]

Definition of 'throwback'

From: GCIDE
  • throwback \throw"back\, n.
  • 1. the reappearance in an organism of characteristics of an earlier ancestral type; atavism. [PJC]
  • 2. an organisms having characteristics of an earlier ancestral type. [PJC] [1913 Webster]