noun
oil tanker
A ship designed to carry crude oil or petroleum products in bulk.
この港には大型の油送船がよく入港する。
Large oil tankers often call at this port.
タンカー is a more general loanword for any tanker ship, while 油送船 specifically refers to oil tankers.
Compound of 油 (oil), 送 (send, transport), and 船 (ship).