† officiˈosityObs.rare. [ad. late L. officiōsitās, f.officiōsus: see -ty.] The quality of being officious; attentiveness, dutifulness. 1565Stapleton tr.Bæda's Hist.Ch.Eng. v. iv. 157 She..ceasyd not to vse such courteous officiosytye, all the dynner time.