to be friendly with each other immediately She hit it off with Dean and soon the two of them set out on a cross-country adventure.We hit it off beautifully – we liked all the same things, and we liked each other a lot.
Get along well together, as in I was so glad that our parents hit it off. In the 17th century this phrase was put simply as hit it, the adverb off being added only in the mid-1800s.