the.com/lap

means The flat space formed across the top of your thighs when you're sitting down.

from From Old English 'læppa,' meaning a loose or hanging flap of a garment — the skirt-fold that gathered over the thighs when you sat. The word slowly drifted from the cloth itself to the hollow it created, until 'lap' meant not the fabric but the feature it formed — a rare case of a word moving from object to the shape left behind it. The 'lap' in a race (one circuit) is a separate, later development, tied to the idea of one edge overlapping another.