say it: SIL-ee
silly is an adjective and noun meaning "ludicrous, foolish". It carries 5 recorded senses.
lacking seriousness; given to frivolity
“a dizzy blonde”
“light-headed teenagers”
“silly giggles”
inspiring scornful pity
“how silly an ardent and unsuccessful wooer can be especially if he is getting on in years”
dazed from or as if from repeated blows
“knocked silly by the impact”
“slaphappy with exhaustion”
“punch-drunk with love”
colloquialism
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for silly come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.