It means The Great One.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

TGO : The Gay One.

TGO is usually used within groups of young people to denote the homosexual within the group. On average young people have only one gay friend, so the label TGO allows others to recognise the homosexual in the group without drawing attention to the fact, which could give rise to an embarrassing social situation for all involved. Especially TGO.

TGO is a term of affection, denoted through the popular chant 'TGO, TGO, TGO' to the rhythm of 'USA, USA, USA'. This chant usually takes place whenever TGO makes a contribution, usually irrelevant, to the group's discussion. This is to let TGO know the group recognises his existence, and do in fact believe he is an important member of the group, despite members of the group muttering other homosexual slander, unbeknown to TGO himself. This chant can on occasion, turn sour, with the group reverting to simply "Gay, gay, gay".

TGO would usually dine on frozen pizza, alongwith a trusty coke, and talk incessantly of penis.

The Great Outdoorsman, a groundbreaking entertainment website, created by part-time cult leader and mango aficionado, Bulgingsnake. It is a trusty news source for the on-the-go professional and the semen crusted shut in alike.

Stands for Trisomic Gene Ordinance. Person with TGO has severe mental issues. Should be used only to describe a medical condition, not to call someone retarded. They tend to live with 2-4gbs of ram since they are unable to upgrade to anything more than windows XP

To be TGO you must be above cool.
See also...fnis