a proposed explanation whose status is still conjectural, a contemplation or speculation
and no 1: a coherent group of general PROPOSITIONS used as principles of explanation for a class of phenomena
scientific -a theory in technical use is a more Or LESS verified or established EXPLANATION accounting for known facts or Phenomena
so it may be their explanation of what they believe to be true, but by no means does it mean it is true, just their best EXPLANTION