Pronunciation: (kō-ak'sē-ul),[key] —adj. 1. Also,co•ax•alPronunciation: (kō-ak'sul).[key]having a common axis or coincident axes.
2. Geom. a. (of a set of circles) having the property that each pair of circles has the same radical axis.
b. (of planes) intersecting in a straight line.
3. (of a loudspeaker) having two or more cones with their centers mounted on the same axis.