Rag
A rag is a low-valued card that is presumably worthless. A hand made of rags, such as seven-two, is one of the worst hands to be dealt.
The simple explanation
When the flop is low and does not help you, it is a ragged flop. A rag on the turn or river is a blank. The hands that are all rags are usually folded before the flop.
A closer look
The word 'rags' can also be used on the board: 'the board is all rags' means that it has low, unconnected cards. Such boards often favor the player who raised before the flop, because he has more high cards in his range. A rag card is a blank on the turn: it does not change the strength of hands much. Calling someone's hand 'rags' is a way to say that it was weak.
A practical example
A player looks at 7♠ 2♦ and says, 'Just rags.' He folds.
Full explanation
A rag is a low-valued card that is presumably worthless. A hand made of rags, such as seven-two, is one of the worst hands to be dealt.
A rag is a low and presumably worthless card.
Hands like seven-two are rags.
A ragged board is a low, unconnected board.
‘Blank’ is a similar term.