the.com/lap
The chair your thighs become, the distance you run in circles, the comfort you offer cats.
means A lap is the flat surface formed by your thighs when seated, one circuit of a course, or the act of drinking with the tongue.
from From Old English laeppa, a loose flap or fold of cloth — your seated thighs make exactly such a fold, and the meanings unspooled from there.
Racing senseFrom the cloth-fold idea: one loop folding back on itself.
Lap of luxuryCoined by playwright Sheridan in 1775.
Drinking lapSeparate Old English root, lapian, to lick up.