a belief that can guide behavior; "the architect has a theory that more is less"; "they killed him on the theory that dead men tell no tales"
a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses"; "true in fact and theory"
marked by or showing unaffected simplicity and lack of guile or worldly experience; "a teenager's naive ignorance of life"; "the naive assumption that things can only get better"; "this naive simple creature with wide friendly eyes so eager to believe appearances"
without a basis in reason or fact; "baseless gossip"; "the allegations proved groundless"; "idle fears"; "unfounded suspicions"; "unwarranted jealousy"