7 letters · 9 points in Scrabble
adjective open and genuine; not deceitful
adjective characterized by a firm and humorless belief in the validity of your opinions
originFrom Middle French sincere, from Latin sincerus (“genuine”), from Proto-Indo-European *sem- (“together”) (whence English sam) + *ḱer- (“grow”) (whence Latin Ceres, the goddess of harvest, etymon of cereal). Not from sine (“without”) + cera (“wax”), a folk etymology; see Wikipedia page.
Etymology from Wiktionary, CC BY-SA 3.0