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.
vague. 1  not clearly or explicitly stated or expressed: vague promises. 2  indefinite or indistinct in nature or character, as ideas or feelings: a vague premonition of disaster. 3  not clear or distinct to the sight or any other sense; perceptible or recognizable only in an indefinite way: vague shapes in the dark; vague murmurs behind a door.