Resting aidsface is kind of like resting bitchface but it describes a person who always look like they are suffering from a bad disease like AIDS. People who have the resting aidsface want to draw attention to themselfs by looking like they just got punched in the stomach, even if they feel good.
Random Person: Hey Donnie, Marvin looks like hes feeling not good. Should I talk to him?
Donnie: Nah thats just his resting aidsface, he'll be fine. And his name is NOT Marvin!