古英語のswete「甘い、心地よい」から、原ゲルマン語*swotja「甘い」から、PIE*swad「甘い」から、語源的にはsuasion「説得する」と同じ。
Then come kiss me, sweet-and-twenty!Also "being in a sound or wholesome state" (mid-13c.), and, of water, "fresh, not salt" (late Old English). As an intensifier from 1958. Sweet in bed (c. 1300) was the equivalent of modern "good in bed." To be sweet on someone is first recorded 1690s. Sweet sixteen first recorded 1767. Sweet dreams as a parting to one going to sleep is attested from 1897, short for sweet dreams to you, etc. Sweet-and-sour in cookery is from 1723 and not originally of oriental food. Sweet nothings "sentimental trivialities" is from 1900. Sweet spot is from 1976, first in reference to tennis rackets. Sweet corn is from 1640s.
Youth's a stuff will not endure.
["Twelfth Night"]