肉 is a picture of a piece of meat — a slab with lines showing the ribs or marbling inside. When it appears inside other characters it shrinks to 月-form (the 'meat radical'), which is why so many body-part characters (脸 face, 胖 fat, 腿 leg) seem to contain 'moon'. They're really meat — flesh.
肉 is meat or flesh: 吃肉 (eat meat — with 吃), 牛肉 (beef), 鸡肉 (chicken), 羊肉 (lamb), 红烧肉 (red-braised pork, a beloved dish). The 'meat radical' 月 hidden in body characters is one of the most useful patterns to learn. Affectionately, parents call a chubby baby 肉肉的 (cute and pudgy). And remember 月 from earlier? When it means meat, not moon, context tells you which.
A slab of flesh with ribs inside — MEAT.
The 'meat radical' (月-form) hides in body-part characters: 脸 (face), 腿 (leg), 胖 (fat) all contain 'meat', not 'moon'. Once you spot it, the body makes sense.