Are yams and sweet potatoes the same?
c.1000, from Old French ymne and Old English ymen, both from Latin hymnus "song of praise," from Greek hymnos "song or ode in praise of gods or heroes," used in Septuagint for various Hebrew words meaning "song praising God." Possibly a variant of hymenaios "wedding song," from Hymen, Greek god of marriage (see hymen), or from a PIE root *sam- "to sing" (cf. Hittite išhamai "he sings," Sanskrit saman- "hymn, song") [Watkins]. Evidence for the silent -n- dates from at least 1530.
occurs only Eph. 5:19 and Col. 3:16. The verb to "sing an hymn" occurs Matt. 26:30 and Mark 14:26. The same Greek word is rendered to "sing praises" Acts 16:25 (R.V., "sing hymns") and Heb. 2:12. The "hymn" which our Lord sang with his disciples at the last Supper is generally supposed to have been the latter part of the Hallel, comprehending Ps. 113-118. It was thus a name given to a number of psalms taken together and forming a devotional exercise. The noun hymn is used only with reference to the services of the Greeks, and was distinguished from the psalm. The Greek tunes required Greek hymns. Our information regarding the hymnology of the early Christians is very limited.