a kind of fragrant herb
菎 centers on a specific fragrant herb, used for its scent or medicinal properties.
菎 combines the grass radical 艹 with 昆, which likely provides the sound コン. The character refers to a type of fragrant plant.
The grass radical 艹 sits above 昆, like a fragrant herb growing over a group of insects (昆 suggests many). Imagine a sweet-smelling plant that attracts swarms of bugs.
For コン, picture a fragrant herb placed inside a conch shell to spread its scent: conch -> コン.
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