The phrase "doeth sly" refers to someone who is being cunning or sneaky. The opposite of this would be someone who is honest and straightforward, without any hidden agenda. Antonyms for "doeth sly" could include words like straightforward, sincere, genuine, honest, trustworthy, and transparent. These are all qualities that are highly prized in relationships, both personal and professional. When someone is not "doeth sly," they are more likely to build and maintain trust with others, which can lead to better communication, stronger relationships, and increased success in both personal and professional endeavors.