【Reveal】 , 【discover】 ,  【disclose】 ,  【divulge】 ,  【tell】 ,  【betray】  can all mean to make known what has been or should be concealed or is intended to be kept concealed.

【Reveal】 implies a setting forth or exhibition by or as if by lifting a curtain that veils or obscures. It can apply to supernatural or inspired revelation of truths beyond or above the range of ordinary human sight or reason or to simple disclosure (as of information or a secret) or it may carry no suggestions of an intentional communication but imply rather an affording of signs or other evidence from which the truth may be inferred.

【Discover】  (see also  【DISCOVER】 2 INVENT ) implies an exposing to view by or as if by uncovering; the term usually suggests that the thing discovered has been hidden from sight or perception but is not, as often in the case of  【reveal】 , in itself beyond the range of human vision or comprehension.

【Disclose】  is more often used in this sense than  【discover】 .

More often  【disclose】 implies the making known of something that has not been announced or has previously been kept secret.

【Divulge】  differs little from  【disclose】 in this latter sense except in often carrying a suggestion of impropriety or of a breach of confidence or in implying a more public disclosure.

【Tell】  (see also COUNT 1 ) may come very close to  【divulge】 in the sense of making known something which should be kept a secret, but more often it implies the giving of necessary or helpful information, especially on request or demand.

【Betray】  (see also DECEIVE ) often implies a divulging of a secret, but it carries either a stronger and more obvious suggestion of a breach of faith or of a disclosure (as through signs or appearances) against one’s will.