Pronounced: so-LOO-nuhr, adj
Notes: It’s probably what you think (but I’ve never seen this word before)
The word miscegenation is “a marriage between different racial groups” (but see comments)
This word came into English in the mid-1800s
Background / Comments
A note on the definition: I’ve run across differences in the definitions; some use the one I provided above, but some add “cohabitation” and “collaboration” in addition to “marriage”, and add “cultural groups” to “racial groups”. During the US Civil War, a journalist named David Goodman Croly wrote an anonymous pamphlet that attempted to discredit the Lincoln administration and the abolitionist movement. He coined the term miscegenation to refer to marriage between blacks and whites. The word was based on the Latin words miscēre (to mix) combined with genus (species, race, stock). Over time, the definition has widened from this rather narrow definition. I noted that I’ve run across this word during reading; it referred to a mixed marriage between different races (not the narrow original meaning).