Gain function (G.B.)
Directive gain (U.S.A.)
For a given direction, 4PI times the ratio of the radiation intensity in that direction to the total power radiated by the antenna.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
centre of gravity
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM