The act of seeing someone else's screen and all of their online activities. This can only be done when both users have a Mac. A screen share is usually a bad thing, as you can essentially take over someone's screen and "creep" on them.
"If you don't stop annoying me, I'm about to screen share you."
My teacher who introduced me to witchcraft, new age spirituality, reiki, and occultism did a spiritual journey where we tapped into each other's minds. It was like screen share of the mind.