from
The Collaborative International Dictionary of English v.0.48
Appui \Ap`pui"\, n. [F., fr. L. ad + podium foothold, Gr. ?,
dim. of ?, ?, foot.]
1. A support or supporter; a stay; a prop. [Obs.]
[1913 Webster]
If a vine be to climb trees that are of any great
height, there would be stays and appuies set to it.
--Holland.
[1913 Webster]
2. (Man.) The mutual bearing or support of the hand of the
rider and the mouth of the horse through the bit and
bridle.
[Webster 1913 Suppl.]
{Point d'appui}. [F., a point of support.] (Mil.)
(a) A given point or body, upon which troops are formed,
or by which are marched in line or column.
(b) An advantageous defensive support, as a castle,
morass, wood, declivity, etc.
(c) any point of support or basis of operations, as a
rallying point.
[1913 Webster +Webster 1913 Suppl.]