Lookups of the word mongrel spiked recently after news spread that '70s rocker and present-day conservative activist Ted Nugent referred to President Obama as a "subhuman mongrel" in an interview he did last month with Guns.com. Nugent is known for his inflammatory remarks, but this one gained attention as he campaigned for Republicans in Texas.
Merriam-Webster defines mongrel as:
an individual resulting from the interbreeding of diverse breeds or strains; especially : one of unknown ancestry
Given Obama's heritage, and the fact that mongrel is frequently wielded as a pejorative, it's easy to understand how the comment struck many as offensive. Not to mention, the word is often used to mean "a dog with parents of different breeds." As for its etymology, mongrel comes from the Middle English word meaning "mixture," and ultimately from the Old English word gemong, meaning "crowd."
Nugent later issued a non-apology apology of sorts. He told radio host Ben Ferguson, "I do apologize—not necessarily to the President—but on behalf of much better men than myself."