Too Smart by Half

The phrase "too smart by half" means someone who is excessively clever, to the point of being devious or overconfident, often leading to negative consequences for themselves.

The origin of the phrase is uncertain, but it is believed to have originated in Britain in the early 19th century. One theory is that it may have originated in the game of poker, where players who were too clever by half would overplay their hand and lose the game. Another theory suggests that it may have come from the theater, where actors who were too clever by half would overact and ruin the play.