蔑 rarely stands alone — it lives almost entirely in compounds:
蔑视 mièshì 'to despise',
轻蔑 qīngmiè 'contempt',
诬蔑 wūmiè 'to slander'. The Shuowen explanation describes eyes 'tired and unfocused' — a hint at the dismissive look that gives the character its meaning of looking down on someone.