apertness en · NOUN
Etymology
From apert + -ness.
Meanings
-
(archaic, uncountable) Openness; frankness.
And in general, the Freedom or Apertneſs and vigour of pronuncing (as is particularly obſerved in the Bocca Romana) and giving ſomevvhat more of Aſpiration; And on the other ſide, the cloſeneſs and Mufling, and (as I may ſay) Lazineſs of ſpeaking […] render the ſound of their Speech conſiderably different, though they all ſhould uſe the ſame Alphabet.
1669, William Holder, Elements of Speech: An Essay of Inquiry into the Natural Production of Letters: […], London: […] T. N[ewcomb] for J[ohn] Martyn printer to the R[oyal] Society, […], →OCLC, page 79: