Gliding angle n. (Aeronautics) The angle, esp. the least angle, at which a gliding machine or aeroplane will glide to earth by virtue of gravity without applied power.
... it. This sailplane only has a gliding angle ratio of one to twenty-five, but it's a workhorse with a payload of some four hundred pounds. A really high performance glider can have a ratio of as much as ... — Mercenary • Dallas McCord Reynolds