The abbreviation of Thetford Forest, a tree plantation in the East of England, straddled across the Norfolk/Suffolk border. Whilst actually just a glorified tree farm it doubles as a leisure centre for a whole host of activities including: rambling, family days/picnics, segwaying, mounting biking, dog/cat walking, deer stalking, casual hedonism and whole host of other passion filled activities. Almost exclusively used by folk originating from East Cambridgeshire 15 years ago; it appears that in recent years that usage has spread nationwide.
Examples "wot u doin this weekend m8?" "fack all buh, goin to Thetty Eff"
"who are ya, who are ya? Thetty, Thetty Eff!"
"Looks like im going to be swinging off a tree at gape on a corporate do" "gape?" "YEAH, THETTY EFF"
by fordting June 23, 2017
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