A support or supporter; a stay; a prop. [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.