Definition: adj 1: agreeably stimulating to the palate ; especially : spicy
2: engagingly provocative; also: having a lively arch charm

Etymology: Middle French, from present participle of piquer

Quotation: “Over the years I got to be quite a connoisseur of soap. Though my personal preference was for Lux, I found that Palmolive had a nice, piquant after-dinner flavor — heavy, but with a touch of mellow smoothness. Life Buoy, on the other hand… YECCHH!”
- from A Christmas Story

I think I actually heard this word spoken before I read it. I heard it in one of my favorite movies — A Christmas Story. It comes up in the voice-over track as Ralphy describes what it was like to be punished with a stick of soap in the mouth. A classic to be sure.
You might also notice that “piquant” is similar in spelling and pronunciation to another recognizable Spanish word — “picante.” I would imagine that is no coincidence.