frank

Synonyms: aboveboard apparent artless bare-faced blunt bold brazen call a spade a spade candid direct downright easy familiar flat-out forthright free from the hip guileless heart-to-heart ingenuous lay it on the line like it is matter-of-fact naive natural open outright outspoken plain plain-spoken real saying what one thinks scrupulous sincere straight straightforward transparent truthful unconcealed undisguised uninhibited unreserved unrestricted up front upright

Antonyms: devious dishonest evasive insincere secretive