sincere

Synonyms: aboveboard actual artless bona fide candid dead-level dear devout earnest faithful forthright frank genuine guileless heartfelt honest to god like it is meant natural no fooling no-nonsense on the level on the line on up and up open outspoken plain pretensionless real regular righteous saintly serious square sure enough true true-blue trustworthy twenty-four carat unaffected undesigning undissembled unfeigned unpretentious up-front wholehearted

Antonyms: dishonest insincere tricky untrustworthy