(colloquial) A silly person.

(endearing, gently derogatory) A term of address.

(colloquial) A mistake.

Laughable or amusing through foolishness or a foolish appearance, particularly when referring to numbers, especially prices that are absurdly large.

(now chiefly Scotland and Northern England, rare) An adjective "silly" represents a pitiful, innocent, helpless, defenseless, insignificant, worthless, sickly, feeble, and infirm state or quality.

(now rural UK, rare) A simple, plain, and rustic or homely characteristic.

Mentally simple, foolish, lacking judgment, mentally retarded (in scotland), and stupefied or senseless.

(cricket, of a fielding position) Very close to the batsman, facing the bowler; closer than short.

(now regional or colloquial) Sillily: in a silly manner.