n. An individual who, in a professional capacity, creates a system or theory in order to account for something that is not understood. A person who poses a Hypothesis, which is a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena.

Latin, subject for a speech, from Greek hupothesis, proposal, supposition, from hupotithenai, hupothe-, to suppose : hupo-, hypo- + tithenai, to place; Indo-European roots.

Literally everyone, ever. Including the writer of this definition.