chi·me·ra also chi·mae·ra 
(kī-mîrə, kĭ-)
(kī-mîrə, kĭ-)n.
1.
a. An organism, organ, or part consisting of two or more tissues of different genetic composition, produced as a result of organ transplant, grafting, or genetic engineering.
b. A gene or protein consisting of parts from two different genes or proteins that are normally distinct, sometimes derived from two different species.
2. An individual who has received a transplant of genetically and immunologically different tissue.
3. A fanciful mental illusion or fabrication.
[Middle English chimere, Chimera, from Old French, from Latin chimaera, from Greek khimaira, female goat, Chimera; see ghei- in the Appendix of Indo-European roots.]