regift
To give someone a gift that was first given to you.
To regift means to give someone a present that was originally given to you. When your aunt gives you a sweater that doesn't fit, and you wrap it up and give it to your cousin for their birthday, you're regifting.
People regift for different reasons. Sometimes you receive duplicate gifts, like getting two copies of the same book. Sometimes a gift just isn't right for you: maybe you get a puzzle about trains when you're really into dinosaurs, but you know your friend loves trains. Rather than let a perfectly good gift sit unused in your closet, regifting lets it go to someone who'll actually enjoy it.
The tricky part about regifting is doing it thoughtfully. You need to make sure the gift actually suits the new recipient and that you're not just passing along something you think is worthless. And you definitely want to avoid regifting something back to the person who originally gave it to you, which would be awkward.
Some people think regifting is practical and environmentally smart. Others feel it lacks the personal thought that makes gifts meaningful. Either way, if you regift, you should remove the old gift tag first.