retinal rod vs rod

retinal rod and rod both are nouns.

Word	Noun	Adjective	Verb	Adverb
retinal rod	Yes	No	No	No
rod	Yes	No	No	No

As nouns, retinal rod and rod are synonyms defined as:

retinal rod and rod: a visual receptor cell that is sensitive to dim light

Other synonyms of retinal rod include rod cell.

retinal rod (noun)	rod (noun)
a visual receptor cell that is sensitive to dim light	any rod-shaped bacterium
	a long thin implement made of metal or wood
	a gangster's pistol
	a visual receptor cell that is sensitive to dim light
	a linear measure of 16.5 feet
	a square rod of land