High-waisted, somewhat loose-fitting jeans said to look like those stereotypically worn by middle-aged moms. The phrase can be used to characterize such jeans as unflattering or simply as a label for the particular fit, which became fashionable after the emergence of the term. Ladies, we're going out tonight, so don't wear your mom jeans! It seems that mom jeans have become the new uniform for hipster girls this summer.