poser

noun

1. 1

   A particularly difficult question or puzzle.

2. 2

   Someone who asks a question or sets a problem.

   “Even as a child, she was a habitual poser of difficult questions.”

3. 3

   Someone who, or something which, poses; a person who sets their body in a fixed position, such as for photography or painting.

4. 4

   A poseur; someone who affects some behaviour, style, attitude or other condition, often to impress or influence others.