Gravy Train Definition

noun

A sinecure, subsidy, etc. that allows one to live luxuriously without much work.

Webster's New World

An occupation or other source of income that requires little effort while yielding considerable profit.

American Heritage

(idiomatic, politics) A gorging on luxuries, since someone else foots the bill.

Wiktionary

Synonyms:

Other Word Forms of Gravy Train

Singular:

gravy train

Plural:

gravy-trains

The word gravy by itself was used prior to any attestable use of gravy train to characterise 'cushy' situations. It is a shortening of the phrase riding the gravy train, rather than train referring to a number of individuals going the same way or a way of teaching people.

From Wiktionary