A man bun dad is a young father, usually of post-grad school age and/or status. Defining characteristics include:

- A hearty man bun
- A startup family with one or two small children
- Carhartt's work pants, folded up to reveal Chaco sandals or an ankle tattoo from youth
- Tee shirt from a brewery or outdoors store in whatever liberal college town they've decided to pitch a nest in
- Promising future with a green tech company or something of that good yuppie nature

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.