"to form hypotheses," 1738, from hypothesis + -ize. Hypothetize is an alternative form, preserving the consonant of the Greek base. Related: Hypothesized; hypothesizing.

"founded on or characterized by a hypothesis, conjectural," 1580s, from Latinized form of Greek hypothetikos "pertaining to a hypothesis," from hypothesis (see hypothesis). Hypothetic (1670s) is less common. Related: Hypothetically.