noun
- a foolish or silly person; a simpleton
Usage: informal; chiefly British; dated
Examples
- Don't be such a ninnyhammer—that was an obvious mistake.
- He acted like a complete ninnyhammer when he forgot his own address.
- The ninnyhammer locked himself out of his own house.
- She called him a ninnyhammer after he mixed up the dates.
- What a ninnyhammer thing to do!