hy·poth·esize hypothesizes hypothesizing hypothesized in BRIT, also use hypothesise If you hypothesize that something will happen, you say that you think that thing will happen because of various facts you have considered. To explain this, they hypothesise that galaxies must contain a great deal of missing matter which cannot be detected I have long hypothesized a connection between these factors. to suggest a possible explanation that has not yet been proved to be true hypothesize that