A dynamic tidal power dam is a long barrier of 30 km or more which is built perpendicular to the coast, running straight out into the sea, without enclosing an area.

Dynamic voltage restoration is a method of overcoming voltage sags and swells that occur in electrical power distribution.

The dynamical stability of a ship at any inclination is defined as the work done in heeling the vessel to that inclination.

A vessel which automatically maintains its position (fixed location or predetermine track) exclusively by the action of its thrusters.

A craft that is operable on or above water and which has characteristics different from those of conventional displacement ships. A craft, which complies with either of the following characteristics would be considered a DSC:

A dynamo is an electrical generator that creates direct current using a commutator.

The dyne is a derived unit of force specified in the centimetre–gram–second (CGS) system of units.

A Dyson sphere is a hypothetical megastructure that completely encompasses a star and captures a large percentage of its power output.