The phrase "hobnob with" means to associate or socialize with someone, usually in a friendly and informal manner. There are several synonyms for this phrase, including mingle, fraternize, consort, hang out, pal around, rub shoulders, and mix. These words all convey a sense of casual and relaxed socializing with others. Other similar phrases include "run with the same crowd," "keep company with," and "be on friendly terms with." Regardless of the term used, it's important to remember that socializing with others is an important part of building relationships and connecting with people on a personal level.