meet up with (one)
To meet or encounter someone, especially in a casual capacity. I'm meeting up with Jenny and David tomorrow for lunch, so I won't be around in the afternoon. I met up with James at the mall yesterday to help him shop for a suit.
meet up with someone or something
to meet someone or something, usually by accident. I met up with Don on the street yesterday. James met up with a strange accident.
meet up with
Encounter, especially by accident, as in We hadn't gone far along the trail when we met up with another mule train. [Colloquial; late 1800s]