from
The Collaborative International Dictionary of English v.0.48
Bower \Bow"er\ (bou"[~e]r), n. [G. bauer a peasant. So called
from the figure sometimes used for the knave in cards. See
{Boor}.]
One of the two highest cards in the pack commonly used in the
game of euchre.
[1913 Webster]
{Right bower}, the knave of the trump suit, the highest card
(except the "Joker") in the game.
{Left bower}, the knave of the other suit of the same color
as the trump, being the next to the right bower in value.
{Best bower} or {Joker}, in some forms of euchre and some
other games, an extra card sometimes added to the pack,
which takes precedence of all others as the highest card.
[1913 Webster]