TV series example of the word

The Big Bang Theory Season 3, Episode 3
Sheldon, you can't train my girlfriend like a lab rat.

The Big Bang Theory Season 8, Episode 22
...of death among train aficionados.

The Big Bang Theory Season 4, Episode 6
"Train day"?

The Big Bang Theory Season 9, Episode 14
A Texas Special cattle and calf car train set with authentic horn and bell!