fat
膋 centers on animal fat or fatty tissue, especially the internal fat around organs.
膋 is a rare character combining 肉 (meat, here as 月) with 勞 (labor) simplified, suggesting fat as a product of bodily effort or rich tissue. The exact historical development is uncertain.
Under a cover (冖), meat (月) is heated by fire (火) until the fat renders out. The dripping fat is 膋.
For リョウ, imagine a lion (ライオン) rendered into fat: the first syllable 'ryo' from a made-up word 'ryon' cues リョウ, and the fatty meat drips over the fire.