Chrism, also called myrrh, myron, holy anointing oil, and consecrated oil, is a consecrated oil used in the Catholic, Eastern Orthodox, Oriental Orthodox, Assyrian, Nordic Lutheran, Anglican, Old Catholic, and Latter Day Saint churches in the administration of certain sacraments and ecclesiastical functions.
The English chrism derives from Koine Greek via Latin and Old French. In Greek, khrîsma (χρῖσμα) was originally the verbal noun ("(the act of) anointing", "unction") of χρίειν ("anoint"). By extension, along with khrîma (χρῖμα), khrîstai (χρῖσται), and later khrísma (χρίσμα), it came to be used for the anointing oil or ointment itself. Khrísma came into Latin as chrisma, which appears in the works of Tertullian. This was adopted directly into Old English as crisma, which developed into Middle English crisme and various related spellings. In Old French, the original Latin was conflated with cramum ("cream"), developing into cresme, which was also borrowed into Middle English around 1300 as creme and various related spellings. The spelling chrism after the Latin original was generally adopted in the 16th century, after which "cream" came to be restricted to its present meaning.
The Proto-Indo-European root from which the Greek term derived has been reconstructed as *ghrei- ("to trickle"). This is cognate with Sanskrit ghṛtə (घृत, from the radix घृ (भासे / क्षरणे / छादने), which means to shine / to trickle / to cover) and Hindi ghī (घी, "ghee"), as well as Lithuanian gr(i)ejù, griẽti ("skimming"), Middle Low German grēme ("grime"), Old English grīma ("mask, helm, spectre", presumably from an original sense of "covering" or "concealment"), English grime, and possibly Phrygian gegreimenan ("painted, ornamented, inscribed").
Chrism can be also a Myron or myrrh. Myron is an oil that is blessed by a bishop.
Multiple early Christian documents discuss the "ordinance" or "several ceremonies...explained in the Apostolical Constitutions" of "chrism", including documents by Theophilus (d. 181) and Tertullian (d. 220).