Scarlett felt pleased at hearing of their exploits, pleased in a proprietary manner.
She rose as he entered, thinking with proprietary pride that he was the handsomest soldier she had ever seen.
At times, he had an ungallant feeling that Honey’s coquetries and proprietary airs were no credit to him, for she was so boy-crazy he imagined she would use them on any man who gave her the opportunity.
There are no more uses of "proprietary" in the book.
Show samples from other sources
Tylenol is a proprietary drug that can be purchased in generic form as acetaminophen.
My employment contract prohibits by sharing proprietary information with people outside of the firm.