IPA: /ˈɪnsiːm/
KK: /ˈɪnˌsim/
The inside line where two pieces of fabric are sewn together in the leg of pants, often used to measure the length of the pants.
I need to check the inseam of these trousers to make sure they fit properly.
Inseam → The word is formed from "in-" (meaning within) and "seam" (from Old English "seam", meaning a line of stitching). The term "inseam" refers to the seam that is located within the leg of a garment, specifically the inner seam of trousers.
Think of the seam being 'within' ('in-') the leg of the pants — that's why inseam refers to the inner seam.