appui

CIDE DICTIONARY

appui, n. [F., fr. L. ad + podium foothold, Gr. , dim. of , , foot.].

•  A support or supporter; a stay; a prop.  [1913 Webster]

  "If a vine be to climb trees that are of any great height, there would be stays and appuies set to it."  [1913 Webster]
•  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.