Dhupa means "incense" in Sanskrit.
The eleventh of sixteen typical upacharas ("offerings") made to a god as part of devotion, following the paradigm of treating a deity as a valued guest.
The god is provided incense to appreciate the aroma of this offering.
The fundamental aim here, as with other upacharas, is to demonstrate one's devotion for the god by ministering to the deity's needs.
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