/fluy"buy'/ , n. , pl. flybys .
1. the flight of a spacecraft close enough to a celestial object, as a planet, to gather scientific data.
2. Aeron.
a. Also called flypast . a low-altitude flight of an aircraft for the benefit of ground observers.
b. flyover (def. 1).
Also, fly-by .
[ 1950-55, Amer.; n. use of v. phrase fly by ]