When used as a label, gay refers to someone who experiences attraction to the same gender, whether it be romantically, emotionally, sexually, or all. Although it's typically used by non-women (men and people on the non-binary spectrum) who are only attracted to other non-women, gay can be used as an umbrella term for practically anyone in the LGBTQIA+ community.
Jude and I are boyfriends; we're gay.
1. likes the same gender
2. being happy
3. a word that every single fatherless kid uses
4. you
To like that dick up your ass even though your a guy
Vincent: Hey Noah what are you craving right now?
Noah: Some of that DICK
Vincent: EW you're so gay!