Y  This is the terminal for cooling or air conditioning and goes to the compressor relay. Typically a thermostat wire pull is made to the air handler on split systems and then this wire is spliced for the separate wire pull which is made to the condenser.
profound (comparative more profound, superlative most profound) 1  Descending far below the surface; opening or reaching to great depth; deep. 2  Very deep; very serious. 3  Intellectually deep; entering far into subjects; reaching to the bottom of a matter, or of a branch of learning; thorough a profound investigationâ. a profound scholarâ.
Definition of quarter. 1  1 : one of four equal parts into which something is divisible : a fourth part in the top quarter of his class. 2  2 : any of various units of capacity or weight equal to or derived from one fourth of some larger unit. 3  3 : any of various units of length or area equal to one fourth of some larger unit.