Recently came across Barron’s Japanese Idioms book at my school library- will upload my blog with idiom regularly. definitions taken from book and yahoo jisho. Japanese definition from zokugo-dict.

油を売るあぶらをうる [to sell oil]
to goof off; to loaf; waste time in idle conversation; dawdle

例:あの人は仕事をするより、油を売るのが得意です。He’s better at goofing off than working

To read about the origins: