/in"seem'/ , n.
1. an inside or inner seam of a garment, esp. the seam of a trouser leg that runs from the crotch down to the bottom of the leg.
adj.
2. of or pertaining to such a seam: inseam measurements.
3. (of a pocket) placed at or sewn to an opening in the seam of a garment, usually the side seam, so as to lie completely inside the garment.
[ 1905-10; IN- 1 + SEAM ]