patency

Noun

 * 1)  The condition or state of being.
 * 2)  The degree of openness (of a tube, such as a blood vessel or catheter); the relative absence of blockage or obstruction. Measured in percent.
 * 3)  Obviousness; clarity.
 * 1)  Obviousness; clarity.
 * 1)  Obviousness; clarity.