Portcullis

Portcullis is the term given to strong, grated doors found in fortresses and castles around the world. These doors are usually made up of iron or other hard-to-break material such as stone.

By the way, where did you hear this term? No, seriously, not even I remember where I first heard it.
Well if there's one thing I think is worth noting is that your vocabulary is definitely expansive (If you found this on your own, that is.)

The portcullis ahead blocks our path, there's no way around it unless we manage convincing those guys to get it out of the way for us.

Bad design

Bad design is attributed to games that have Gameplay artifacts that unfairly punish the player should they not do as the game orders of them.
Bad design can also be exacerbated by games punishing players simply because they didn't know any better.

Terraria's boulder trap removes up to 400 HP instantly despite the fact players are not allowed to see it; A crystal-clear example of bad design.

Furthermore, they are not made aware of its existence until much later on in the game, meaning if they've attained valuable items it's all lost in a matter of seconds without the chance of retaliation.