Source : Webster's Revised Unabridged Dictionary (1913)

Comprehensibility \Com`pre*hen`si*bil"i*ty\, n.
   The quality or state of being comprehensible; capability of
   being understood.

Source : WordNet®

comprehensibility
     n : the quality of comprehensible language or thought [syn: {understandability}]
         [ant: {incomprehensibility}]