from
The Collaborative International Dictionary of English v.0.48
Armil \Ar"mil\, n. [L. armilla a bracelet, fr. armus arm: cf.
OF. armille.]
1. A bracelet. [Obs.]
[1913 Webster]
2. An ancient astronomical instrument.
[1913 Webster]
Note: When composed of one ring placed in the plane of the
equator for determining the time of the equinoxes, it
is called an equinoctial armil; when of two or more
rings, one in the plane of the meridian, for observing
the solstices, it is called a solstitial armil.
--Whewell.
[1913 Webster]