The term isn't even specific to M/F. It's a general concept of two [or more] combining. M/M, M/F, F/F, and more would all be chimera and even when adding on specifics it doesn't change the fact it's still a topic about a chimera.

Hell, Icewind Dale 2 even has the Legion of the Chimera as the main antagonist group and involves various [evil DND] races that are chimera in some way. The leaders are two Cambions with an army of kobolds, Neo-orogs [orc/ogre hybrids], half-dragons, half-otherthings because they are all a chimera in some way or another and share a sense of rejection from the world as they don't truly belong to what groups make up their heritage.