Ky-meer-ah, but you can of course say shim-er-ah just to vary it a bit...all I know is that they used the first one when they said chimera in Mission Impossible 2
VARIANT FORMS: also Chi·mae·ra
NOUN: 1. Greek Mythology A fire-breathing she-monster usually represented as a composite of a lion, goat, and serpent. 2. An imaginary monster made up of grotesquely disparate parts.