A bag containing oil or for containing oil; (Nautical) a bag used to drip oil on to the sea to calm the waves. Also (formerly): †a bag to contain a substance from which oil is to be expressed (obsolete).
Origin
Late 17th century. From oil + bag.
Definition of oil bag in US English:
oil bag
nounˈɔɪl ˌbaɡ
A bag containing oil or for containing oil; (Nautical) a bag used to drip oil on to the sea to calm the waves. Also (formerly): †a bag to contain a substance from which oil is to be expressed (obsolete).