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]

Moby Thesaurus II by Grady Ward, 1.0:

72 Moby Thesaurus words for "genotype":
   DNA, DNA double helix, RNA, allele, antetype, anticodon, antitype,
   archetype, biotype, branch, class, classic example, codon,
   criterion, deoxyribonucleic acid, epitome, family, fugleman,
   fugler, gene, gene complex, gene flow, gene pool, genetic drift,
   genus, hereditary character, heredity, imitatee, kingdom, lead,
   mRNA, messenger RNA, mirror, model, nucleotide, operator gene,
   operon, order, original, paradigm, pattern, phylum, precedent,
   prototype, regulator gene, representative, ribosomal RNA, rule,
   section, series, species, standard, structural gene, subclass,
   subfamily, subgenus, subkingdom, suborder, subspecies, subtribe,
   superclass, superfamily, superorder, superspecies, tRNA,
   transfer RNA, tribe, type, type species, type specimen, urtext,
   variety