Metagaming meaning

Metagaming: In role-playing games, a player is metagaming when they use knowledge that is not available to their character in order to change the way they play their character (usually to give them an advantage within the game), such as knowledge of the mathematical nature of character statistics, or the statistics of a creature that the player is familiar with but the character has never encountered. In general, it refers to any gaps between player knowledge and character knowledge which the player acts upon.