justly (adv.)youdaoicibaDictYouDict[justly 词源字典]
early 14c., "in an adjacent position, closely," from just (adj.) + -ly (2). Meanings "truthfully, honestly," "in an equitable manner, with justice, fairly" are from late 14c. Sense of "justifiably, with good reason" is from c. 1400; that of "legally, legitimately, rightfully" is early 15c.[justly etymology, justly origin, 英语词源]