Definitions

1. noun

The seam that runs along the outside of a garment, especially a pair of trousers, from the top of the waistline to the bottom of the hem.

“To take in the outseam of the trousers, I had to let out a few inches of fabric.”

2. verb

To take in or let out the outseam of a garment, especially trousers.

“The tailor had to outseam the trousers to fit the customer’s legs.”