Dolt (noun)

1. A stupid or foolish person.
2. A person who lacks sense or understanding.

Origin:

From the middle english word "dolte" meaning "stupid person".

Examples:

1. He"s a complete dolt, he can"t even tie his own shoes.
2. The company's decision to invest in that venture was made by a group of dolts.
3. He was called a dolt for his inability to understand the instructions.
4. The dolt couldn't even figure out how to make a cup of tea.
5. The dolt's lack of common sense was astounding.