olein

As nouns the difference between olein and olefin

is that olein is any naturally-occurring greasy or oily substance related to fat while olefin is any of a class of unsaturated open-chain hydrocarbons such as ethylene; an alkene with only one carbon-carbon double bond.

In chemistry terms the difference between oleic and olein

is that oleic is of or pertaining to oleic acid or its derivatives while olein is any glyceride of oleic acid.

As an adjective oleic

is of or pertaining to oil, especially to vegetable oil.

As a noun olein is

any naturally-occurring greasy or oily substance related to fat.