When L.C. asked me if I knew what a Vesper was, I said "Sure, one of those 2-cylinder European cycles that gets 100 miles to a gallon." She assured me that she didn't have an accent, and wasn't talking about Vespa, but Vesper.
I knew it was a canonical hour, that's about it. Actually, Vesper refers to the evening, particularly the evening star, Venus. It also is a bell rung in the evening, an evening service, the sixth canonical hour or its service, held in the evening, or a part of the Roman Catholic office to be said in the evening.
But that's not what she meant either. She meant Vesper the drink. Well, I thought I knew my drinks pretty well, but this had me stumped. It seems a vesper is a drink James Bond had a bartender make him in Casino Royale, described here in Esquire (the whole article's pretty good):
3 ounces London dry gin
1 ounce vodka
1/2 ounce blonde Lillet
Lillet, apparently is a French aperitif wine which is mixed with two strong clear spirits (gag me), and then shaken or stirred, depending if you are pro- or anti- Bond, and then strained into a champagne flute and garnished with a lemon twist. Sounds pretty girly to me.
L.C. and Stryder had been in Vegas and met a young woman at a bar who was drinking vespers. And apparently was sober enough to describe what went into them.
[Image from Bond Lifestyle. Looks like a martini glass to me. He specifically asked for a champagne flute. I think he'd send it back, don't you?]