What is the word used to describe a person who believes nothing can be known for sure?
The word used to describe a person who believes that nothing can be known for sure is agnostic.
Complete the following task based on the instruction and optional input provided.### Instruction:
What is the word used to describe a person who believes nothing can be known for sure?

### Output:
The word used to describe a person who believes that nothing can be known for sure is agnostic.