Word of the day - "Lagniappe"

It's not often I come across a word that is new to me. From the following Wall Street Journal article: Healthy Ridicule

 Excerpt:

It actually hadn't occurred to us that the Romney line was a repudiation of global warmism. If so, that's lagniappe. What we enjoyed was the deft way in which Romney punctured Obama's self-aggrandizement--by quoting his most immodest promise ever, pausing for effect, then making an almost comically modest promise of his own.

Comment: Here's the Merriam-Webster definition: Lagniappe