From The Collaborative International Dictionary of English v.0.48 :
Conventionality \Con*ven`tion*al"i*ty\, n.; pl. Conventionalities. The state of being conventional; adherence to social formalities or usages; that which is established by conventional use; one of the customary usages of social life. [1913 Webster]From WordNet (r) 3.0 (2006) :
conventionality n 1: conformity with conventional thought and behavior 2: unoriginality as a result of being too conventional [ant: unconventionality] 3: orthodoxy as a consequence of being conventional [syn: conventionality, convention, conventionalism] [ant: unconventionality]