kind of hoe
櫌 refers to a kind of hoe, a farming tool used for breaking up soil or smoothing the ground.
櫌 combines 木 (tree/wood) with 憂, which likely contributes the sound. The character is associated with a wooden farming tool, a kind of hoe.
The left side 木 suggests wood, and the right side 憂 looks complex like a tool. Picture a wooden hoe with an intricate head, used for smoothing the soil.
For ユウ, imagine using the hoe while saying 'you' as you work: you -> ユウ, and you smooth the earth with the wooden tool.