Armillary \Ar"mil*la*ry\, a. [LL. armillarius, fr. L. armilla arm ring, bracelet, fr. armus arm: cf. F. armillaire. See Arm, n.]

Pertaining to, or resembling, a bracelet or ring; consisting of rings or circles.

Armillary sphere, an ancient astronomical machine composed of an assemblage of rings, all circles of the same sphere, designed to represent the positions of the important circles of the celestial sphere. --Nichol.

Source: Webster's Revised Unabridged Dictionary (1913)