garlic
葷 centers on strong-smelling vegetables, especially garlic, which are traditionally avoided in certain Buddhist contexts.
葷 combines the grass radical 艹 with 軍, which likely contributes the sound. The character originally referred to strong-smelling vegetables like garlic.
The grass radical 艹 on top of 軍 (army) suggests a plant so pungent it could repel an army—garlic.
For クン, imagine a cook named Kuhn who always adds too much garlic: Kuhn -> クン, and his kitchen reeks of 葷.
—
meat and the five pungent roots (avoided in Buddhist cuisine)
five pungent roots (in Buddhism or Taoism)
strong-smelling vegetable (esp. garlic, onion, Chinese chives, Chinese scallion, Japanese garlic)
pungent vegetables and raw-smelling meat
pungent vegetable (e.g. onion, garlic, leek)
pungent vegetable (e.g. garlic, onion)
pungent vegetables (e.g. garlic or Chinese chives) and alcohol; leeks and liquors
bringing pungent vegetables or liquor inside the temple is prohibited