vanaspati

As a proper noun Vanaspati

is name of a rāgam in Carnatic music. It is the fourth melakarta rāgam of the 72 melakarta rāgams of Carnatic music.

As a noun margarine is

a spread, manufactured from a blend of vegetable oils (some of which are hydrogenated), emulsifiers etc, mostly used as a substitute for butter.

As nouns the difference between vanaspati and butter

is that vanaspati is (botany) the entire plant kingdom or trees that bear fruits but no evident flowers while butter is butter.