Why don't you be a baclony person and lift him up by telling him you think he's nice and that you don't think he's weird annoying loud bad breath nerd geek bi etc but that's only if you feel that way.
Be his friend, or more if you like him.
If you don't help him out at all by defending him, you're just allowing them to continue. He needs allies in the least. Be one, you won't regret it.
stand up for him tell him what you think of him no one has the right to judge
Why do you care what others think about him. It's your thoughts and feelings that count. Can you stand up and take the challenge that others may disapprove? Time to show your character. Do what is right, not what is the easiest thing to do.
The easy thing would be to join everyone else or not get involved. The right/hard thing would be to stick up for the guy and get others to leave him alone.
all those people must be so great being so perfect. Who cares what everyone else says. What you should do is what you think you should do. What do you think you should and can do about it?
Have the guts to make your own judgements about friends, is my best advice.
I followed that advice some of the time back in high school, but looking back I wish I had done it more.
Help him help himself.