rag A low-valued (and presumably worthless) card. I don't like playing ace-rag from that position. Hence "ragged"/"raggy" - having a low value: The flop was pretty ragged, so I figured my queens were good. Though note that if a flop consists of consecutive or same-suited low-value cards then it is not ragged/raggy, as it could be valuable as part of a straight or flush.
rail The rail is the sideline at a online hold'em poker table—the (often imaginary) rail separating spectators from the field of play. Watching from the rail means watching a online hold'em poker game as a spectator. "Going to the rail" usually means "Losing all one's money".