Dingdong (noun)

1. A sound of a bell or a knock.
2. A stupid or foolish person.

Origin:

The origin of this word is uncertain, but it is believed to have originated as a reduplication of the word "ding" which is used to describe the sound of a bell or a knock.

Examples:

1. The doorbell went dingdong and woke me up.
2. The dingdong of the alarm clock was hard to ignore.
3. He's such a dingdong, he never listens to anyone.
4. The manager's attitude made him come across as a complete dingdong.
5. I can"t stand working with that dingdong, he"s always so negative.