[chi.me.ra] n [L chimaera, fr. Gk chimaira she-goat, chimera; akin to ON gymbr yearling ewe, Gk cheimon winter--more at hibernate] 1 a cap: a fire-breathing she-monster in Greek mythology having a lion's head, a goat's body, and a serpent's tail b: an imaginary monster compounded of incongruous parts
2: an illusion or fabrication of the mind; esp: an unrealizable dream "a fancy, a ~ in my brain, troubles me in my prayer --John Donne"
3: an individual, organ, or part consisting of tissues of diverse genetic constitution