Theorize/ˈθiːəraɪz,ˈθɪraɪz/ Definition 1 of 2Pro Tip 1/3Academic Tone Used in scientific or scholarly discussion, not casual conversation. Researchers theorize that this gene influences human behavior. Pro Tip 2/3Explaining Phenomena Often used when discussing why or how something happens, particularly in nature or science. Astronomers theorize how black holes form in space. Pro Tip 3/3Professional Conjecture Common in expert analysis where proof is incomplete, but educated guesses are made. Economists often theorize about market trends.