neomorph

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. a gain of function mutation that causes novel gene function.

from the GNU version of the Collaborative International Dictionary of English

• n. A structure, part, or organ developed independently, that is, not derived from a similar structure, part, or organ, in a preexisting form.

from The Century Dictionary and Cyclopedia

• n. In biology, a part or organ, or a modification of a part or organ, which has recently been generated or acquired.