tummler

noun

1. (US)An employee, usually male, of a Borscht Belt resort charged with the duty of entertaining guests throughout the day by providing any number of services, from comedian to master of ceremonies.

   “Brooks began as a Tummler (master entertainer) at various Catskills resorts, where he honed his skills at telling jokes and doing impersonations.”

2. A lively, mischievous man.
3. (broadly)A person with an official role which involves facilitating social interaction.

   “But most of all, we can’t forget why we needed moderators in the first place: They’re our tummlers, helping us have a good time.”