BINGO is a slang term used in Scrabble for a play using all seven of one’s tiles.
A player who does this receives 50 points in addition to what the word would normally score.
Since “bingo” only has 5 letters, it can never be a BINGO.
However, it is a legal word … unlike NONGO.
NONGO is a slang term used in SCRABBLE for a BINGO you have on your rack that you can’t find a place to play on the board.
“Nongo” is not a legal word, so even if you have it on your rack and can find a place to play it, it’s just TDB.
TDB is also not a legal word.