In gaming, the act of forcing a player to "choose to" do something they don't really want to in order to advance the plot according to the wishes or designs of the GM.
Thus, the player feels like they're being moved through a world (or plot) as if on train tracks, without any choice on where to go.
"So we have to search the lower dungeon to find the key, despite the fact that this door is rotten and my character has 19 strength? Stop railroading us!"
when you feed your partner refried beans, broccoli, and French onion soup, and a few hours later, have them crawl around the house on their hands and knees while you plow their ass, so they let out little steam-engine farts with each stroke. Bonus points if you put on an engineer's hat and sing the "Thomas the Tank Engine" theme.