They could discuss it privately when they got home.
Privately, she willed the boy away.
He was privately educated before entering the university.
He privately gloated at his finesse; I think I'm going to break a record here.
He was educated privately and was so precocious a boy as to translate a Latin version of the Battle of the Frogs and Mice into French in 1796, which was published by his father in 1797.