gotcha

noun

1. 1

   A potential problem or source of trouble.

   “Review the work thoroughly and make sure there are no gotchas.”

2. 2

   An instance of publicly tricking someone or exposing them to ridicule, especially by means of an elaborate deception.

3. 3

   An instance of accomplishing a tricky idea or overcoming a difficult obstacle.

   “Now here's another few gotchas that you can do to implement it.”

4. 4

   A feature of a system or a program that works in the way it is documented but is counter-intuitive and almost invites mistake or non-function.

   “Wireless was the first gotcha when installing the distro.”