潜艇

Dunker \Dun"ker\, prop. n. [G. tunken to dip.]
One of a religious denomination whose tenets and practices
are mainly those of the Baptists, but partly those of the
Quakers; -- called also {Tunkers}, {Dunkards}, {Dippers},
and, by themselves, {Brethren}, and {German Baptists}, and
they call their denomination the Church of the Brethren.

Note: The denomination was founded in Germany in 1708, but
after a few years the members emigrated to the United
States; they were opposed to military service and
taking legal oaths, and practiced trine immersion.
[1913 Webster + WordNet 1.5]

{Seventh-day Dunkers}, a sect which separated from the
Dunkers and formed a community, in 1728. They keep the
seventh day or Saturday as the Sabbath.

Dunbird \Dun"bird`\, n. [Named from its color.] (Zo["o]l.)
(a) The pochard; -- called also {dunair}, and {dunker}, or
{dun-curre}.
(b) An American duck; the ruddy duck.