What is the X in X-mas?
late 14c., "receiving, collection," from Latin perceptionem (nominative perceptio) "perception, apprehension, a taking," from percipere "perceive" (see perceive). First used in the more literal sense of the Latin word; in secondary sense, "the taking cognizance of," it is recorded in English from 1610s. Meaning "intuitive or direct recognition of some innate quality" is from 1827.
perception per·cep·tion (pər-sěp'shən)
The process, act, or faculty of perceiving.
Recognition and interpretation of sensory stimuli based chiefly on memory.