Pat
Mixed-game term
To stand pat is to take no cards when it is your turn to draw. You keep all five, and the deck stays where it is.
It announces that your hand is already made, because that is usually true — and every player at the table watches you do it. That visibility is the whole reason standing pat is also a bluff worth having.
Nothing left to improve
7♣
5♠
4♥
3♦
2♠
✓ the best hand in 2-7 — drawing can only ruin it
→ How to play 2-7 Triple Draw, from the rules up.