burn, kindle, build a fire, boil, cook
焚 centers on using fire to transform something: burning fuel, kindling flames, building a fire, or cooking by applying heat.
焚 combines 林 (woods) and 火 (fire), suggesting a fire built from wood. The character likely originated as a depiction of burning trees.
Picture a forest 林 set ablaze with a fire 火 underneath: the trees burn, kindling a great fire that can be used to boil water or cook food.
For フン, imagine the fun of a campfire: fun -> フン, as you burn wood and cook over the flames.
to burn; to kindle; to light (a fire); to make (a fire)
open-air fire (e.g. for garden refuse); bonfire; campfire
book burning
kindling; firelighter
Kyoto area festival held on the 11th lunar month (wherein bonfires are burned at shrines)
to burn aromatherapy oils; to diffuse aromatherapy oils
daikon-offering ceremony (Ryotokuji temple, Kyoto)
having few faults as well as few virtues; not burning agarwood (incense); not passing wind
building a fire
Kyoto area festival held on the 11th lunar month (wherein bonfires are burned at shrines)
to light (a fire); to kindle
bonfire often in temple grounds, usu. of charms, talismans, New Year decorations, etc.
door (of a furnace, stove, etc.); fuel hole
to perfume clothes by burning incense
fire pit; outdoor brazier; bonfire stand
firewood
burning at the stake
pillaging and setting fire to
burning books on the Chinese classics and burying Confucian scholars alive (Qin dynasty thought suppression campaign)
room with a sunken hearth