silly

Concise Oxford English Dictionary © 2008 Oxford University Press:
silly/ˈsɪli/

▶adjective (sillier, silliest)

• 1 lacking in common sense or judgement; foolish.

• 2 trivial or frivolous.

• 3 archaic helpless; defenceless.

• 4 Cricket denoting fielding positions very close to the batsman: silly mid-on.

▶noun (pl. sillies) informal a silly person.

– phrases
the silly season high summer, regarded as the season when newspapers often publish trivial material because of a lack of important news.

– derivatives
sillily adverb,
silliness noun.

word history: Silly entered English (spelled seely) in the 13th century from a Germanic source, in the senses ‘happy, blissful’ and ‘lucky, auspicious’. From this the senses ‘spiritually blessed’ and ‘pious and holy’ arose. A subtle development in meaning from ‘innocent, harmless’ (often referring to animals) to ‘deserving of pity’ led to ‘feeble’ and then, from the early 16th century, ‘foolish, simple’. The spelling silly is recorded from the 15th century.