The Collaborative International Dictionary of English v.0.48:
Intelligibility \In*tel`li*gi*bil"i*ty\, [Cf. F. intelligilibilit['e].] The quality or state of being intelligible; clearness; perspicuity; definiteness. [1913 Webster]WordNet (r) 3.0 (2006):
intelligibility n 1: the quality of language that is comprehensible [ant: unintelligibility]