black bamboo, slender bamboo
篶 refers to a type of bamboo, specifically black bamboo or slender bamboo. The meaning is narrow and concrete, centered on this particular plant.
篶 combines 竹 (bamboo) with 焉, which likely provides the sound エン. The character was created to name a specific bamboo variety.
The top 竹 shows it's a bamboo. The bottom 焉 looks like a slender, dark shape, like a black bamboo stalk with its leaves.
For エン, imagine the slender black bamboo bending in the wind, forming the shape of the letter 'N': N -> エン.