All 3 Uses

hypothesis
in
Great Expectations
(Edited)

A little later on in the dinner, Mr. Wopsle reviewed the sermon with some severity, and intimated—in the usual hypothetical case of the Church being "thrown open"—what kind of sermon he would have given them.
p. 26.1 *

hypothetical = something temporarily treated as true to advance a discussion or to further investigation
You say they are marks of finger-nails, and you set up the hypothesis that she destroyed her child.
p. 417.8

hypothesis = a seemingly reasonable, but unproven, idea
You must accept all consequences of that hypothesis.
p. 417.9 *

Definitions:

(1) (hypothesis as in: a study to test her hypothesis)
a seemingly reasonable, but unproven idea or explanation based upon known facts

In casual conversation, theory is a synonym for hypothesis, but a scientist would say that a hypothesis needs to pass rigorous tests before it could be accepted as a theory.
(2) (hypothesis as in: assume as a working hypothesis)
something that may or may not be true, but is temporarily treated as true to advance a discussion or to further investigation

This sense of hypothesis is typically seen in the form, hypothetical, or hypothetically.
(3) (meaning too rare to warrant focus)