Source : Webster's Revised Unabridged Dictionary (1913)

Train oil \Train" oil`\ (oil`). [D. or LG. traan train oil,
   blubber (cf. Dan. & Sw. tran, G. thran) + E. oil.]
   Oil procured from the blubber or fat of whales, by boiling.

Source : WordNet®

train oil
     n : a white to brown oil obtained from whale blubber; formerly
         used as an illuminant [syn: {whale oil}]