sil·ly / ˈsilē/ • adj. (-li·er, -li·est) having or showing a lack of common sense or judgment; absurd and foolish: another of his silly jokes “Don't be silly!” she said. ∎ ridiculously trivial or frivolous: he would brood about silly things. ∎ used to convey that an activity or process has been engaged in to such a degree that someone is no longer capable of thinking or acting sensibly: he often drank himself silly his mother worried herself silly over him. ∎ archaic (esp. of a woman, child, or animal) helpless; defenseless.• n. (pl. -lies) inf. a foolish person (often used as a form of address): Come on, silly.PHRASES: the silly season high summer, regarded as the season when newspapers often publish trivial material because of a lack of important news.DERIVATIVES: sil·li·ly / ˈsiləlē/ adv.sil·li·ness n.