Leaking shut-off valve. How to fix?
New homeowner here, and I loosened off the shut-off valve from the basement to my garage faucet today. I'm finding that the part of the valve that I circled is leaking when I open the valve fully. I thought it might go away after a minute or two but it kept leaking (consistent drops of water). The handle also leaked water for a little bit, but it went away after 5-10 seconds. I've since tightened the valve again. For context, right before winter came I tightened the shut off valve and there were no problems at that point.
I've been trying to search for videos of how to fix this, but I can't find exactly what this part of the valve is called. It looks like I could simply try to tighten this part of the valve with a wrench or something, but wanted to get some second opinions here before I go ahead and make things worse.
Thanks in advance!
Edit: Didn't look close enough, could have posted in the plumbing thread but I can't delete this thread now