A lame joke, pun, or play on words that your mom would say, such as "have a nice trip, see you next fall". Does not have to be told by your mom, just has to be lame.

A mom joke is when someone makes a joke and laughs really hard at it but no one else does. It's pretty much PAST the "fake laugh joke" point.

When a hilarious joke is told only to be followed by a lame attempt to make it funnier by useing a cheesy comparison. Usally made by a mom/mother.