The Collaborative International Dictionary of English v.0.48:

Mendelian \Men*de"li*an\, prop. a. [See Mendel's law.]
   1. (Biol.) Pert. to Mendel, or to Mendel's law; as, Mendelian
      inheritance.
      [Webster 1913 Suppl.]

   2. (Biol.) Behaving or being in accordance with Mendel's laws
      of inheritance; -- said of the distribution of inherited
      characteristics and of traits thus distributed. --
      Men*de"li*an*ism, Men*del"ism, n.
      [Webster 1913 Suppl. +PJC]

WordNet (r) 3.0 (2006):

Mendelianism
    n 1: the theory of inheritance based on Mendel's laws [syn:
         Mendelism, Mendelianism]