To masturbate by rubbing or penetrating the vagina. The female version of jerk off.
"Jane likes to twig off two or three times a day." "Last night, her boyfriend twigged her off in the car."
A boy who you're talking to and basically dating, but its not official or titled.
Jen and Tom texted and hung out everyday, but she isn't calling Tom her boyfriend. Tom is her boyfriend non boyfriend.