appears good but is bad, type of weed which resembles rice
莠 centers on something that looks desirable but is actually worthless or harmful, like a weed that mimics a useful plant. The core idea is deceptive appearance hiding a bad reality.
莠 combines 艹 (grass/plant) with 秀 (excellent/outstanding), likely suggesting a plant that appears excellent but is actually a weed. The exact historical development is uncertain.
The grass top 艹 sits above 秀, which means excellent. Picture a weed that looks just like a prize-winning rice plant, but it's actually a worthless impostor.
For ユウ, imagine a farmer saying 'you!' to the deceptive weed, realizing it's not the excellent plant it pretended to be: you -> ユウ.