n.同义反复，赘述；恒真命题； 变形： 复数：tautologies 英英释义： tautology[ tɔ:'tɔlədʒi ]n.(logic) a statement that is necessarily true"the statement `he is brave or he is not brave' is a tautology"useless repetition"to say that something is `adequate enough' is a tautology"