a. Not corresponding or similar in position, value, structure, or function; not homologous.
b. Biology Relating to traits, such as organs or body parts, that do not correspond in structure or evolutionary origin.
2. Derived from a different species: a heterologous transplant; a heterologous gene.
3. Genetics Relating to chromosomes that do not normally pair during mitosis or meiosis.
4. Relating to cells or tissues that do not usually occur in a given part of the body: a heterologous tumor.
a. Relating to a vaccine or serum that confers immunity against a pathogen that is not identical to but is immunologically related to the pathogen used to create the vaccine or serum.
b. Relating to an antigen and antibody that do not correspond to one another.
het′er·olo·gy (-jē) n.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.