slough (plural sloughs) 1  The skin shed by a snake or other reptile. That is the slough of a rattler; we must be careful. 2  Dead skin on a sore or ulcer. This is the slough that came off of his skin after the burn.
The name Groupon is a combination of the words group and coupon, which references the company's viral marketing business model.
I just bought two groupons as gifts. Depending on the type of groupon and what it is for, the recipient might know that you spent half (or whatever the discount is). One of the groupons I gave was for a tea set, and I used the groupon myself, had the set shipped to me, and wrapped it.