The Collaborative International Dictionary of English v.0.48:

genotype \gen"o*type\ n. (Genetics)
   A group of organisms sharing a specific genetic constitution.
   [WordNet sense 1]
   [WordNet 1.5]

   2. (Genetics) The genetic constitution of an organism,
      specifying the particular alleles at defined loci in the
      genome; -- used with respect to one gene, a specific group
      of genes, or the entire set of genes within the organism.
      Contrasted with phenotype.

   Syn: genetic constitution.
        [WordNet 1.5 + PJC] genotypic

WordNet (r) 3.0 (2006):

genotype
    n 1: a group of organisms sharing a specific genetic
         constitution
    2: the particular alleles at specified loci present in an
       organism [syn: genotype, genetic constitution]