The act of inserting a funnel into ones anus, whilst shitting through it into another persons mouth, straining the nutrients and waterier contents of the shit. Variations may involve the addition of a liquid such as urine for easier consumption.
Person 1: Fuck dude, I'm feeling so queazy right now, I think my shitters gonna blow.
Person 2: Well don't just waste it in your undies dude, want to do a Tunnel Funnel?
Person 1: I'm down for a good old Tunnel Funnel. Thanks man, your the best older brother ever.
Funneling is the act of a group of friends effectively getting a particular girl to disregard them and tell her what she wants to hear in order to "funnel" her to a certain other friend . The opposite of cock-blocking. Often associated with the term "wingman", this maneuver generally incorporates multiple wingmen acting as a single unit working towards the same ultimate objective; to get a buddy laid.
This maneuver is never to be used to funnel the DUFF to another buddy, but can be used to dump her on an unsuspecting douche bag.
"Ok guys, we gotta give this broad The Funnel. That nigga Glasgow hasn't had pussy in a coon's age.