Nuts
The best possible hand on a given board
Definition
The 'nuts' refers to the best possible hand given the visible community cards (the board). Having the nuts means you can't lose the hand — you can only hope to extract maximum value from your opponent. The nuts change on every street based on the new community cards. On an A♦K♦7♦ board, any player with two diamonds already holds an ace-high flush (the A♦ is on the board); the nuts therefore goes to whoever holds the Q♦ — the highest diamond still available — along with another diamond. If the board becomes A♦K♦Q♦J♦, the nuts becomes the royal flush, held by any player with the T♦. The concept of the nuts is central to range construction: value ranges on big sizings are often built around the nuts and near-nuts. Identifying who has the nut advantage on a given board (the player whose range contains more nutted hands) is a key skill of GTO analysis.
Board A♥K♥Q♥. The absolute nuts is J♥T♥ (royal flush). With 9♥8♥ you have an ace-high flush (A-K-Q-9-8), strong but beaten by any hand holding the J♥ or the T♥ — a higher flush — and crushed by the royal flush itself. With JT without a heart, you have the broadway straight (the best hand among non-flushes) but losing to any flush.