
...capable of following
that TRAIN of thought.
The Big Bang Theory Season 1, Episode 5

"Go to the TRAIN store"?
The Big Bang Theory Season 7, Episode 3

Oh, I have no idea.
I never left the TRAIN station.
The Big Bang Theory Season 8, Episode 1

I want to TRAIN with you.
Game of Thrones Season 7, Episode 4

Look at what he bought me
at the TRAIN store.
The Big Bang Theory Season 12, Episode 8