silly

Etymology

A later form of Middle English sely, seli,^[1][2][3] inherited from Old English gesǣlig (“happy, fortunate, blessed”),^[4][2][5] related to sǣl “happiness”,^[4][3] from Proto-Germanic *sæligas.^[4] Compare German selig (“blessed”).^[4]

The meaning shifted remarkably: from “happy” to “blessed”, “pious”, “innocent” (c. 1200), “harmless”, “pitiable” (late 13th century), “weak” (c. 1300), and finally “foolish” (1570s).^[4] Compare nice, whose meaning developed almost in reverse.^[5]

Adjective

silly

1. Lacking good sense; foolish.^[2][3][6]
2. Frivolous, not serious.^[2][3]
3. Absurd or laughable.^[6][5]
4. Dazed, stunned, as in knocked silly.^[2][3][6]
5. (cricket) Of a fielding position: very close to the batsman.^[6][5]
6. (archaic) Weak and helpless; also simple, rustic.^[3][6][1]

Noun

silly

1. (informal) A silly person.^[6][5]

References

1. [1] [2] Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
2. [1] [2] [3] [4] [5] The American Heritage Dictionary of the English Language, Boston: Houghton Mifflin
3. [1] [2] [3] [4] [5] [6] Merriam-Webster's Collegiate Dictionary, Springfield, Mass.: Merriam-Webster
4. [1] [2] [3] [4] [5] Harper, Douglas, Online Etymology Dictionary, https://www.etymonline.com
5. [1] [2] [3] [4] [5] Wiktionary, the free dictionary, https://en.wiktionary.org
6. [1] [2] [3] [4] [5] [6] Random House Webster's Unabridged Dictionary, New York: Random House