Definition of operosity in US English:

operosity

noun

rare
  • Operose character or quality; laboriousness, painstaking endeavour; elaborateness.

Origin

Early 17th century; earliest use found in George Abbot (1562–1633), archbishop of Canterbury. From classical Latin operōsitās elaborateness of construction, in post-classical Latin also laboriousness, painstaking endeavour (late 2nd or early 3rd cent. in Tertullian) from operōsus + -tās.

Pronunciation

operosity

/ˌɒpəˈrɒsɪti/