petrol vs napalm

petrol and napalm both are nouns.

Word	Noun	Adjective	Verb	Adverb
petrol	Yes	No	No	No
napalm	Yes	No	No	No

As nouns, napalm is a hyponym of petrol; that is, napalm is a word with a more specific, narrower meaning than petrol:

petrol: a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines
napalm: gasoline jelled with aluminum soaps; highly incendiary liquid used in fire bombs and flamethrowers

Other hyponyms of petrol include leaded gasoline, leaded petrol, unleaded gasoline, unleaded petrol.

petrol (noun)	napalm (noun)
a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal-combustion engines	gasoline jelled with aluminum soaps; highly incendiary liquid used in fire bombs and flamethrowers