Flush
A hand containing any five cards in the same suit like 5 spades, 5 diamonds.

Flat Top
A video poker machine that does not have a Progressive Jackpot. So the Jackpot amount remains the same.

Four of a Kind
A hand containing four cards of the same denomination like 7-7-7-7_K. The fifth is irrelevant.

Full House
Three of a kind plus a pair like 10-10-10-K-K.
Full Pay
The best payout schedule offered for a particular game. For example, 9/6 Jacks or Better as opposed to 8/6 Jacks or Better, and any game with a full pay schedule plus a progressive jackpot. A video poker machine where the Maximum Average Payback is near 100%. For example, a Full Pay Jacks or Better machine has a Maximum Average Payback of about 99.5%, and a Full Pay Deuces Wild machine has a maximum average payback of about 100.7%

G
Garbage Hand
A bad hand which will let you win nothing. A garbage hand if dealt, should be discarded.
Gut Shot
Another term for an Inside Straight

H
Hand
The five cards, whether dealt or held is considered to be your hand.

High Card
A Jack, Queen, King or Ace. If you are playing Tens or Better Video Poker, then the 10 is also a high card. Wild or joker cards can also be considered high cards.
Hold
The cards you nominate to keep in any given hand.

Hopper
The internal tray that holds the video poker machine coins. The hopper electronically counts coins to be paid and releases them into the player's tray.

House
The establishment running the game.

I
Inside Straight
Four cards to a straight where the one card you need to complete the straight is in the middle of the run. For instance, with a 4c-5h-7d-8c you would need a six of any suit to complete the straight.
Inside Straight Flush
The same as an inside straight except that the cards must all be of the same suit.

J
Jackpot
A special bonus paid when you hit the highest hand on a video poker machine such as a Royal Flush or a Progressive Jackpot
Jacks or Better
Jacks or better is the original video poker game, with a Pair of Jacks as the minimum winning hand. The Full Pay version of Jacks or Better pays 9 credits for a Full House and 6 credits for a Flush on a single coin bet (9/6). Jacks or Better has a Maximum Average Payback of about 99.5%
Joker Poker
A Video Poker Game where the Joker is a wild card. Mostly these have the minimum payout for Kings or Better.