What is the X in X-mas?
Old English hearpe, from Proto-Germanic *kharpon- (cf. Old Saxon harpa "instrument of torture;" Old Norse harpa, Dutch harp, Old High German harpfa, German Harfe "harp"). Late Latin harpa, source of words in some Romanic languages, is a borrowing from Germanic. Meaning "harmonica" is from 1887, short for mouth-harp. The harp seal (1784) is so called for the harp-shaped markings on its back.
Old English hearpian; see harp (n.). Cognate with Middle Dutch, Dutch harpen, Middle High German harpfen, German harfen. Figurative sense of "talk overmuch" (about something) first recorded mid-15c., originally to harp upon one string. Related: Harped; harping.
(Heb. kinnor), the national instrument of the Hebrews. It was invented by Jubal (Gen. 4:21). Some think the word _kinnor_ denotes the whole class of stringed instruments. It was used as an accompaniment to songs of cheerfulness as well as of praise to God (Gen. 31:27; 1 Sam. 16:23; 2 Chr. 20:28; Ps. 33:2; 137:2). In Solomon's time harps were made of almug-trees (1 Kings 10:11, 12). In 1 Chr. 15:21 mention is made of "harps on the Sheminith;" Revised Version, "harps set to the Sheminith;" better perhaps "harps of eight strings." The soothing effect of the music of the harp is referred to 1 Sam. 16:16, 23; 18:10; 19:9. The church in heaven is represented as celebrating the triumphs of the Redeemer "harping with their harps" (Rev. 14:2).