Is there a reason you can't just hold on to it until you need a bottle of red to serve to guests or to give to someone you believe would enjoy it?
No, no reason other than where to store it for any length of time without it going off* . . . in my fridge? On a shelf in the basement? My summer-hot garage? . . . that's how ignorant I am about wine.
I really don't know anybody that drinks red wine. I even offered it to my daughter (now that she's legal age) to drink or give to one of her friends. She said "No, thanks."
I'm assuming you don't care for this wine, since you didn't mention drinking it yourself (although previous posters have made a good point that you can cook with it). It's perfectly fine to regift it, but if you are giving it to someone who doesn't drink wine and/or to someone to whom you would not ordinarily give a hostess gift, I think you should explain the situation (Outdoor Girl's wording sounds good). Without the explanation, it would be strange and awkward to give to someone that you know doesn't drink wine, and in a situation where you don't normally give hostess gifts, it could inadvertently change the dynamic (the next time that person came over, they might wonder if they should bring a hostess gift, and before you know it, you've started a whole thing).
Bold above is exactly what I want to avoid so I don't think I'll bring it to the party, nor even mention it.
Using it for cooking is an excellent thought! (Look for my thread in the Recipe's topic . . . cooking with wine!
*And, if I don't use the whole bottle for cooking:
Or open it and make red wine vinegar and use it to make salad dressing.
I use red wine vinegar quite often for salad dressings, gravies, etc. Is there any trick/recipe for making this out of a bottle of wine? I've never heard of this before.
Thanks, all, for your responses!
(edited to add a comma.)