Where did that term/saying come from?

[nonameo]

Where does the term "gravy train" come from?

 

[theprodigalrebel]

http://www.etymonline.com/index.php?term=gravy

gravy 1381, from O.Fr. grané (with -n- misread for -u- -- the character used for -v- in medial positions in words in medieval manuscripts) "sauce, stew," probably originally "properly grained, seasoned," from L. granum "grain, seed." Meaning "money easily acquired" first attested 1910; gravy train (1927) was originally railroad slang for a short haul that paid well.