A Hand with four Cards of the same Suit.
When four cards to a flush appear on the board, giving every player with just 1 card of the particular suit to make the flush. Particularly annoying when you flop a flush but are holding generally "weak" kickers. The board then "four flushes" on the turn and gives others holding a higher card of that suit a chance to beat you.
n. Four cards to a flush.
Four cards of the same suit, such as four hearts, together with an odd card.