1. That property of an antenna by virtue of which it radiates or receives more strongly in some directions than in others.
2. This term is also used in the U.S.A. for Power gain (4-1-365).
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM