"Met privately" is a commonly used phrase that refers to a meeting that takes place in an intimate or confidential setting. However, there are several other synonyms that can be used to describe similar situations. Alternatives may include "held a closed-door meeting," "conferred behind closed doors," "held a discreet discussion," "had a confidential conversation," "conducted a secret meeting," and "held a one-on-one discussion." These phrases all imply a level of privacy or secrecy in the meeting, and can be used interchangeably depending on the context and tone of the conversation.