the quality of being deep; deepness; perpendicular measurement downward from the surface, or horizontal measurement backward from the front; as, the depth of a river; the depth of a body of troops.-profoundness; extent or degree of intensity; abundance; completeness; as, depth of knowledge, or color.-lowness; as, depth of sound.-that which is deep; a deep, or the deepest, part or place; the deep; the middle part; as, the depth of night, or of winter.-the number of simple elements which an abstract conception or notion includes; the comprehension or content.-a pair of toothed wheels which work together.