The term CAP SITE is composed of three words: KNEE (4 letters), LENS (4 letters), and OILWELL (7 letters). KNEE is a joint in the middle of the leg connecting the thigh and the lower leg. LENS is a curved piece of glass or plastic used to focus light rays, often found in eyeglasses or cameras. OILWELL is a deep hole drilled into the ground to extract oil from underground reservoirs. Together, these three words form the term CAP SITE, which is an area where oil wells are capped off to prevent the release of oil and gas.