The person at the dinner table or party with a smartphone who gets asked to fact-check the conversation on Wikipedia, Google, etc.

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy

One who wikis everything people tell them to.