The word theory has a number of distinct meanings in different fields of knowledge, depending on their methodologies and the context of discussion. In science, a theory is a mathematical or logical explanation, or a testable model of the manner of...

A hypothesis (from Greek ὑπόθεσις) consists either of a suggested explanation for a phenomenon or of a reasoned proposal suggesting a possible correlation between multiple phenomena. The term derives from the Greek, hypotithenai meaning "to put...

Speculation - speculating on the value of financial instruments (shares, futures, derivatives...)

Speculative fiction

Speculator, New York

Speculation (card game)

Speculative philosophy and Speculative reason