recessive

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Tending to go backward or recede.
2. adj. Genetics Of, relating to, or designating an allele that does not produce a characteristic effect when present with a dominant allele.
3. adj. Of or relating to a trait that is expressed only when the determining allele is present in the homozygous condition.
4. n. Genetics A recessive allele or trait.
5. n. Genetics An organism having a recessive trait.

Century Dictionary and Cyclopedia

1. Tending to recede; receding; going back: used especially of accent regarded as transferred or moved backward from the end toward the beginning of a word. In Greek grammar the accent is said to be recessive when it stands as far back from the end of the word as the laws of Greek accentuation permit—that is, on the antepenult if the ultimate is short, or on the penult if the ultimate is long.
2. In biology, opposed to dominant, 2. See recessive, n.
3. n. In biology, an organism that manifests and transmits to descendants the character which is antagonistic to a dominant, or a character which is antagonistic to a dominant character. See dominant, 2.

Wiktionary

1. adj. Going back; receding.
2. adj. genetics Able to be covered up by a dominant trait.

GNU Webster's 1913

1. adj. Going back; receding.
2. adj. (Genetics) Not appearing in the phenotype unless both alleles of the organism have the same trait; -- of genetic characteristics, or of the genes coding for such characteristics, in diploid organisms. Opposite of dominant.
3. n. (Genetics) A genetic trait determined by a recessive{2} allele; a trait not appearing in the phenotype unless both chromosomes of the organism have the same allele; also, an allele which is recessive{2}.

WordNet 3.0

1. adj. (of genes) producing its characteristic phenotype only when its allele is identical
2. adj. of or pertaining to a recession
3. n. an allele that produces its characteristic phenotype only when its paired allele is identical