The stinkhole is the 120th hole on the cribbage board, one short of winning the game. It's so called because you really don't want to find yourself there!
A commonly-used optional rule has it that if you're in the stinkhole, you can't peg out on a Jack (two for his heels) or a go. Sometimes this also applies if you need 5 or fewer points to win. While this is not part of the standard Cribbage rules, you are free to use this rule so long as all players agree on it beforehand.
The official ACC cribbage tournament rules specifically say that this score still counts even if the dealer would peg out and win the game as a result:
Rule 6.3. Scoring When The Starter Card Is a Jack (His Heels)
a. When a Jack is turned up, the dealer is entitled to two points.
b. The dealer may peg out into the game hole by turning a Jack starter card.