You can't focus on studying if you're chatting with someone else, too. So the cell phone is off limits. Turn off the home phone, too, along with the computer (unless you're prepping on it) and any music with vocals. Study music should be lyric-free! Post a sign on your door for people to stay away.
cuirass (plural cuirasses) 1  A piece of defensive armor, covering the body from the neck to the girdle. 2  The breastplate taken by itself.
A triangular fold or flap of a heart valve. cusp. Etymology: L, cuspis, point. 1 a sharp projection or a rounded eminence that rises from the chewing surface of a tooth, such as the two pyramidal cusps that arise from the premolars. 2 any one of the small flaps on the valves of the heart, as the ventral, dorsal, and medial cusps of the right atrioventricular valve. cusp A rigid, sharp point, especially on a leaf Cardiology One of the triangular segments of the pulmonic or aortic valve which opens and closes with the flow of blood