robot bomb vs doodlebug

robot bomb and doodlebug both are nouns.

Word	Noun	Adjective	Verb	Adverb
robot bomb	Yes	No	No	No
doodlebug	Yes	No	No	No

As nouns, robot bomb and doodlebug are synonyms defined as:

robot bomb and doodlebug: a small jet-propelled winged missile that carries a bomb

Other synonyms of robot bomb include buzz bomb, flying bomb, V-1.

robot bomb (noun)	doodlebug (noun)
a small jet-propelled winged missile that carries a bomb	the larva of any of several insects
	a small jet-propelled winged missile that carries a bomb
	a small motor vehicle