obelisk n.

"tapering rectangular stone column with a pyramidal apex," 1560s, from French obélisque (16c.) and directly from Latin obeliscus "obelisk, small spit," from Greek obeliskos "small spit, obelisk, leg of a compass," diminutive of obelos "a spit, pointed pillar, needle, broach; obelisk; bar of metal used as a coin or weight," a word of uncertain origin; according to Beekes, "clearly Pre-Greek." In printing, "a sign resembling a small dagger" (1580s). In dictionaries it is used to mark obsolete words. Greek obelos also was "a mark used in writing; horizontal line used as a diacritic." Related: Obeliscal; obeliskine.