crismon

Etymology
🇨🇬; the meaning "chrism" is attested in the 12th century, apparently by corruption of, from. The meaning "Christogram" is of origin; Millin (1817) suggests derivation from specifically in the instance of the "Chrismon Sancti Ambrosii" (i.e. the "oracle of St. Ambrose), an ancient Chi-Rho symbol on a marble slab in Milan cathedral, from which the term chrismon would have been transferred to the Chi-Rho symbol in general.

Noun

 * 1) Christogram, chrismon Chi-Rho monogram
 * 2) chrism
 * 3) * c. 1130: "In sabbato secundo de Quadragesima, duo minores custodes septimanarii debent quærere cilicium ab archiepiscopo, et debent portare in medio ecclesiæ, et facere Chrismon super illud decurrere." L. A. Murator, Antiquitates Italicae medii aevi  vol. 4, col. 912.