Selected Chess Terms

battery - two pieces that move in the same pattern are stacked (rook+rook, queen+rook,queen+queen,bishop+bishop)
Alekhine's gun - 2 rooks and 1 queen are stacked.
double pawns - when you have two pawns on the same file
File - the vertical lines on the board
Rank - the horizontal lines on the board
open file - a file with no pawns on it
semi-open file - a file with 1 pawn on it
closed file - a file with two or more pawns on it
Zwischenzug(absolute counter attack?) - is a chess tactic in which a player, instead of playing the expected move (commonly a recapture), first interposes another move posing an immediate threat that the opponent must answer
Zugzwang - a very bad position in which whatever you move, your position becomes worse.
counter attack - instead of defending, attack in order to buy time and ask if your opponent want to move his attention elsewhere
Tempo - a tempo is a "turn" or single move. When a player achieves a desired result in one fewer move, the player is said to "gain a tempo"; conversely, when a player takes one more move than necessary, the player is said to "lose a tempo".
absolute deflection - a distractng move that forces the king to move to another square in order to free a previously controlled square
relative deflection - an attack meant to bait a piece to move to another square in order to free a previously contolled square
back-ranker - a checkmate performed on the back rank (first rank of your opponent's side) and hsi pieces are blocking him from escaping
active piece - the more squares it controls the more active it is
passive piece - opposite of active piece
closed position - a position where there are many pawns that aredefensing each other and therefore closing the two sides of the board
Exchange - in a big exhange, if you win more material, you win the exchange. if you lose material, you lose the exchange
interference/obstruction/blocking - a piece is placed between two connected opponen's piecs that break their connection
pawn island - a group of pawn defending each other on the board
isolated pawn - a pawn that cannot be defended by other pawns
backward pawn - is one that has no support from other pawns (because they have advanced ahead of the backward pawn or because they no longer exist).
Outpost -is a square on the fourth, fifth, sixth, or seventh rank which is protected by a pawn and which cannot be attacked by an opponent's pawn.Such a square is a hole for the opponent

fiachetto - in the oppening prepare a bishop to attack one of the diagonals from the 2nd/7th rank and 2nd file by first moving a pawn up
bishop pair - the two bishops are controlling two diagonals next to each other
Connected pieces - two pieces that are defending each other
hanging piece - a piece that is not defended and vulnerable to attacks
flagging - moving aimlessly to win on time when having few seconds on the clock
Botez gambit - a joke term referring to blundering your queen.
Overloading - happens in chess when a piece is given too many defensive duties at the same time by a player and cannot execute them properly. These defensive roles can include the protection of pieces or key squares as well as the blockade of files, ranks, or diagonals.
Weak piece - a piece that is attacked by more pieces and defended by less peices
sacrifice - giving more material in order to gain better position or achiveve a plan
Gambit - a pawn sacrifice in the oppening that gains better position. Gambits are theory moves.
Trapped piece - A trapped piece is a piece that has no escape squares or squares where it can safely move without being captured.
Windmill - A windmill in chess (sometimes also referred to as a seesaw) is a tactic that occurs when one player takes advantage of a restricted king to deliver multiple checks and discovered checks in sequence. Doing so usually allows the player employing the windmill to capture enemy pieces, checkmate the opponent, or force a draw.
major = involves the queen. absolute = involes the king
Fork - a piece attacking two(or more) pieces at once
Pin - attacking a piece in a line that is defending a MORE valuable piece
scewer - attacking a piece in a line that is defending a LESS valuable piece
absolute Fork - a piece attacking two pieces at once, once of which is the king
relative Fork - a fork not involving the king or queen
Major Fork - a piece attacking two pieces at once, once of which is the queen.
double attack - two pieces attack one or two pieces at the same time (+ major/absolute/relative)

absolute pin - one of your pieces(rook/queen/bishop) attacks another piece  that cannot be moved, because it's protecting the king.
relative pin - one of your pieces(rook/queen/bishop) attacks another piece that is protecting a MORE valuable piece
Major pin - one of your pieces(rook/queen/bishop) attacks another piece that is protecting a the queen
absolute scewer(reversed pin) - one of your pieces(rook/queen/bishop attacks the king that is protecting a piece
relative scewer(reversed pin) - one of your pieces(rook/queen/bishop attacks another piece that is protecting a LESS valuable piece
major scewer(reversed pin) - one of your pieces(rook/queen/bishop) attacks a queen that is protecting a LESS valuable piece
revealed attack - you move one piece that exposes an enemy's piece to a previously x-ray attack
revealed check - a peice isi moved to reveeal a check on the king
Revealed check with _____  -   a revealed check that also applies another trap
x-ray - one of your pieces(rook/queen/bishop) attacks indirectly an opponent's piece. It can be obscured by one or more of your pieces, but it turns into a discovered attack once they are moved.
Taking advantage of ____ - to take advantage o a trap(or a weak position) to set another trap
reveealed check
and then you combine then:
revealed double attack
revealed scewer
revealed fork
revealed pin
etc...