napalmPronunciation: /ˈneɪpɑːm/Translate napalm | into Italian Definition of napalm noun [mass noun] a highly flammable sticky jelly used in incendiary bombs and flame-throwers, consisting of petrol thickened with special soaps. verb [with object] attack with bombs containing napalm. Origin: 1940s: from na(phthenic) and palm(itic acid)napalm in other Oxford dictionaries Definition of napalm in the US English dictionary