Etymology: < French cavin < Old French cavain, < Latin cavus hollow.
Military.
A hollow way or natural hollow, sufficiently capacious to hold a body of troops, and facilitate their approach to a fortress.In Bailey, Johnson, and modern dictionaries.
ΚΠ
1708 J. KerseyDict. Anglo-BritannicumCavin, a hollow Way: In the Art of War, a hollow Place, proper to cover Troops, and favour their Approaches to a Fortress.
This entry has not yet been fully updated (first published 1889; most recently modified version published online June 2018).