American Heritage Dictionary
(3)
Century Dictionary
GNU Webster's 1913
(1)
WordNet
(1)
Elsewhere on the web
Not to mention napalm, herbicides and all kinds of sophisticated land mines.— The Full Feed from HuffingtonPost.com
In its simplest terms, napalm is a jellified form of petroleum that can be used in aerial bombardments to create fires.— Latest Articles
One day Kim spoke to a group of U.S. veterans and recalled the napalm incident.— CommonDreams.org Headlines
As in Korea, napalm was also used along with other incendiary devices.— SteveLendmanBlog

American Heritage Dictionary (1)
Bubble size: how much this word was used in a year
Bubble height: used more or less than expected, vs. all uses evenly distributed
You can expect to see this word a few times a year.