mingle
To move around and chat with different people socially.
To mingle means to mix together or move among a group of people, talking and socializing. At a party, when you mingle with the guests, you move around, chat with different people, maybe meet someone new, instead of staying in one spot with the same person. You're mixing yourself into the crowd.
The word works for things mixing together too. When you stir hot chocolate, the powder mingles with the milk. When different spices mingle in a soup, their flavors blend and combine. Morning fog mingles with smoke from chimneys.
But people use mingle most often for social situations. A good host at a party mingles with all the guests, not just their closest friends. After a school concert, families mingle in the lobby, sharing congratulations and conversation. Someone might encourage a shy person to go mingle instead of standing alone in the corner.
The word suggests a pleasant, relaxed kind of mixing. You wouldn't say armies mingled on the battlefield, even though they're certainly mixing together. Mingling has a friendly, social feeling to it, like ingredients in a recipe that make something better by combining, or people at a gathering making the event more interesting by talking with each other.