Hole

This is one of the few strategic terms in the batch with a named coiner supported by reference sources. Britannica, in its account of Steinitz and the theory of equilibrium, states that he originated the term hole to mean a vulnerable square that has lost its pawn protection and can be occupied favourably by an enemy piece. The Chess Skills blog cites Hooper and Whyld's The Oxford Companion to Chess (1992), page 175, which defines a hole as a square on a player's third rank or beyond that cannot be guarded by a pawn, and states that the concept originates in the writing of Wilhelm Steinitz. The same source reports that Steinitz wrote in The Modern Chess Instructor (1889) that he had first used the term in The International Chess Magazine of November 1886, which gives a specific self-reported first use. Wikipedia's glossary carries the modern definition, a square inside or near a player's territory that cannot be controlled by a pawn, describing it as a gap in the pawn configuration that is especially dangerous near the centre or the king, with the e4-square in the Stonewall Attack as an example.

First documented: 1886 — Wilhelm Steinitz in The International Chess Magazine, November 1886, as stated by Steinitz himself in The Modern Chess Instructor (1889) and reported via Hooper and Whyld, The Oxford Companion to Chess (1992), p. 175