From Wiktionary, the free dictionary
Blend of knight + nightmare.
knightmare (plural knightmares)
- (chess, humorous, informal) A figurative nightmare involving a knight, e.g. a crushing knight move or a hopeless situation involving a knight.
2020 March 11, Isaak Linder, Vladimir Linder, Mikhail Botvinnik: Sixth World Chess Champion[1], SCB Distributors, →ISBN, →OCLC:16...Nbxd5? The wrong knight captures, which leads to a knightmare for Black.
2020 November 17, Thomas Engqvist, 300 Most Important Chess Positions[2], Batsford, →ISBN, →OCLC, page 138:17...cxd5? 18 ♘b5 is obviously a “knightmare” for Black.
