Theory Theory synonyms hypothesis theory and hypothesis speculation theory and speculation assumption theory and assumption thesis theory and thesis supposition theory and supposition conjecture theory and conjecture postulate theory and postulate premise theory and premise philosophy theory and philosophy idea theory and idea Full list of synonyms (675) Theory antonyms fact theory and fact certainty theory and certainty proof theory and proof reality theory and reality truth theory and truth knowledge theory and knowledge information theory and information disbelief theory and disbelief calculation theory and calculation measurement theory and measurement Full list of antonyms (12) Share this picture Share this image Share this picture Share this image