ˈ ̷ ̷| ̷ ̷ adjective
: having a right-handed screw propeller and a left-handed screw propeller parallel to each other one on each side of the plane of the keel — compare single-screw
ˈ ̷ ̷| ̷ ̷ adjective
: having a right-handed screw propeller and a left-handed screw propeller parallel to each other one on each side of the plane of the keel — compare single-screw
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012