piercing (adj.)

early 15c., percing, in reference to cold, sound, light, a gaze, etc., present-participle adjective from pierce (v.). Figuratively, of the effect on the mind or emotions of pain, grief, etc., "sharp, keen, intense," from late 14c. Related: Piercingly.

piercing (n.)

late 14c., "act of penetrating with a point;" c. 1400, "a perforation, a hole," verbal noun from pierce (v.).