What is Sotto Voce?
1.
From the Italian, meaning 'low voice'. To speak quietly out of the corner of your mouth so that the subject of your speech can't hear your insult or know that you are speaking.
"Oh, what a beautiful creature your daughter is", said Mrs. Mulroy saccarinely to Mrs. Katz at the Bat-mitzvah.
"Too bad the zoo can't identify what kind of creature she is", Mrs. Jackson said sotto voce to Mrs. Mulroy as they plastered wide smiles on their faces.