A cup of homebrew coffee that is exceptionally strong, bitter or laxative.

A throwback to the poor quality coffee produced by American fathers who would buy ground coffee in bulk, and do little to nothing to prevent it from oxidizing and going stale.
GIRL: This coffee is so bitter!
BOY: Yea, I'm sorry that came out like dad coffee today.
by NewYorkNewerPork August 4, 2019
Get the dad coffee mug.