gas pump vs petrol pump

gas pump and petrol pump both are nouns.

Word	Noun	Adjective	Verb	Adverb
gas pump	Yes	No	No	No
petrol pump	Yes	No	No	No

As nouns, gas pump and petrol pump are synonyms defined as:

gas pump and petrol pump: a pump in a service station that draws gasoline from underground storage tanks

Other synonyms of gas pump include gasoline pump, island dispenser.

gas pump (noun)	petrol pump (noun)
a pump in a service station that draws gasoline from underground storage tanks	a pump in a service station that draws gasoline from underground storage tanks