Source : Webster's Revised Unabridged Dictionary (1913)

Piercing \Pier"cing\, a.
   Forcibly entering, or adapted to enter, at or by a point;
   perforating; penetrating; keen; -- used also figuratively;
   as, a piercing instrument, or thrust. ``Piercing eloquence.''
   --Shak. -- {Pier"cing*ly}, adv. -- {Pier"cing*ness}, n.

Source : WordNet®

piercingly
     adv 1: extremely and sharply; "it was bitterly cold"; "bitter cold"
            [syn: {bitterly}, {bitingly}, {bitter}]
     2: in a shrill voice; "she sang rather shrilly" [syn: {shrilly}]