■ noun
1》 the regularly repeated elliptical course of a celestial object or spacecraft about a star or planet.
↘the path of an electron round an atomic nucleus.
2》 a field of activity or influence: they brought many friends within the ~ of our lives.
3》 Anatomy the eye socket.
■ verb ( ~s , ~ing , ~ed ) move in ~ round (a star or planet).
↘put (a satellite) into ~.
Phrases
into ~ informal into a state of heightened activity, anger, or excitement.
Derivatives
~er noun
Origin
C16: from L. ~a 'course, track', feminine of ~us 'circular'.