Losing a hand in poker that you from the beginning are very probable to win. Often (or so it will seem) to a worse player, who called you bet when the odds were clearly against him/her.
Novices often confuse a bad call with a call that will probably lose, but still has the pot odds on its side. They will then moan and moan about getting bad beaten when in fact they were only slightly unlucky. A bad beat is in fact when someone makes an incorrect move against you, and gets extremely lucky.
Good player: My pocket kings got called with Q9 when flop was K-9-A and I went all in. Turn was a 9. River came the last 9. Losing to runner-runner nines. Well, that´s poker.

Bad player: I had pocket nines and went all in for 2 dollars. This rich guy called me with AKs and caught an ace. Now that´s a bad beat! I hate this game!
by Krisse July 18, 2005
In gambling, when it would appear the outcome of an event is virtually decided, and suddenly, at the very last, ( or near very last) moment, the script gets flipped, and the predicted winning ticket is now a LOSER.
He suffered a Bad Beat when his horse, who was about to win the race, jumped a shadow, and fell into the rail, dislodging the jockey, interestingly, in the shadow of the finish line, disqualified.
by Danny Durden May 26, 2021
Bad Beat is all about when ur mates toss u a low blow, when things are just not called for, when you started way ahead but got outdrawn, when someone gives u the cold shoulder, when someones not up for heading out etc
You still coming out tonight?
Nah i cant..

Lunch today?
by wiper110 July 4, 2013
Poker phrase about an improbable loss on a hand of cards. Means that you started the hand way ahead but got outdrawn, thus you suffered a bad beat.

Many casinos and card rooms offer extra incentives and jackpots for very bad beats (such as losing with four of a kind).
Playing Texas Hold-Em'...

I have 2-3
You have A-A

Flop comes A-2-K
Turn is a 2
River is a 2

In this hypothetical, I put a bad beat on you since your three Aces was way out in front of my pair of 2's after the flop.
by ACG2x December 30, 2005
In poker, usually, it is when you lose a hand that seemed like it was going to win to a person who got extremely lucky.

Usually followed by a very pointless bad beat story
The biggest bad beat I can remember is when I had pocket queens and the flop was:

Q44. The other guy had KJ and caught two runner Kings for the higher full house.

I was 99.4% favored to win the pot.
by Cds April 18, 2005
Bad-Beat is a nickname used by an internet forum poster who can sometimes be seen on different forums, internet chats and other internet related things. If you spot him, give yourself 10 points. The name 'Bad-Beat' can only be written with capitals 'B's. If you ever write the name with small b's then you are said to have 'failed'. The reason for the capital B's goes back to the 4th century, when farmers in Southern England would be working in the fields growing potatoes all the while spouting out new words and phrases. The many terms that Shakespeare has been creditted to can actually be traced back to these farmers. One day the farmers decided that some structure should be used in their phrases, the first new phrase that they invented after this grammar shift was, Bad-Beat, where they added in multiple capital letters, the first in history and a hyphen.
Bad-Beat likes a fine wine and cheese.
by Deano139 August 16, 2006
Someone who just lost a hand (usually in poker) and will bemoan about it to anyone who listens online.

Most of the time, the listeners do not give a shit about the other person's bad beat.

See bad beat
Noob at poker: My 2-7 offsuit lost to AA when the flop came 2-7-9. The turn was a 9!! HOW LUCKY CAN HE GET?

Good person at poker: Like I care.
by Cds April 18, 2005