1. the quality or state of being friendly and familiar in a casual, informal way
Usage: informal; usually positive connotation

Examples

• The chumminess between the two old friends was evident as they laughed and joked together.
• She appreciated the chumminess of the small office where everyone knew each other well.
• The coach's chumminess with the players helped build team morale.
• There was a sense of chumminess at the reunion as classmates reconnected.
• He tried to establish chumminess with his new coworkers by joining them for lunch.
• The chumminess of the neighborhood made it a great place to raise a family.