oiler vs tanker

oiler and tanker both are nouns.

Word	Noun	Adjective	Verb	Adverb
oiler	Yes	No	No	No
tanker	Yes	No	No	No

As nouns, oiler and tanker are synonyms defined as:

Other synonyms of oiler include oil tanker, tank ship.

oiler (noun)	tanker (noun)
a cargo ship designed to carry crude oil in bulk	a cargo ship designed to carry crude oil in bulk
a well that yields or has yielded oil	a motor vehicle designed to carry liquefied loads, dry bulk cargo or gases on roads.
a worker who oils engines or machinery	a soldier who drives a tank