Webster’s Revised Unabridged Dictionary · 1913
Silly
Sil′ly, a. [Compar. Sillier; superl. Silliest.] [OE. seely, sely, AS. s?lig, ges?lig, happy, good, fr. s?l, sēl, good, happy, s?l good fortune, happines; akin to OS. sālig, a, good, happy, D. zalig blessed, G. selig, OHG. sālīg, Icel. sæl, Sw. säll, Dan. salig, Goth. sēls good, kind, and perh. also to L. sollus whole, entire, Gr. ὅλος, Skr. sarva. Cf. Seel, n.] 1. Happy; fortunate; blessed. [Obs.] Chaucer.
2. Harmless; innocent; inoffensive. [Obs.] "This silly, innocent Custance." Chaucer.
The silly virgin strove him to withstand. Spenser.
A silly, innocent hare murdered of a dog. Robynson (More's Utopia).
3. Weak; helpless; frail. [Obs.]
After long storms . . . With which my silly bark was tossed sore. Spenser.
The silly buckets on the deck. Coleridge.
4. Rustic; plain; simple; humble. [Obs.]
A fourth man, in a sillyhabit. Shak.
All that did their silly thoughts so busy keep. Milton.
5. Weak in intellect; destitute of ordinary strength of mind; foolish; witless; simple; as, a silly woman.
6. Proceeding from want of understanding or common judgment; characterized by weakness or folly; unwise; absurd; stupid; as, silly conduct; a silly question.
Syn. — Simple; brainless; witless; shallow; foolish; unwise; indiscreet. See Simple.