the gorilla in the room什么意思

The following article is quoted from wikipedia, hope it helps:

The elephant in the room (also elephant in the living room, elephant in the corner, elephant on the dinner table, elephant in the kitchen, horse in the corner, etc.) is an English idiom for an obvious truth that is being ignored. It is based on the fact that an elephant in a small room would be impossible to overlook.

A similar idiom is 800 pound gorilla in the room. This apparently originates from a blend of elephant in the room with a separate idiom, "800 pound gorilla," meaning a powerful contender. (Where does an 800 pound gorilla sit? Wherever he wants!)

It sometimes is used to refer to a question or problem that very obviously stands to reason, but which is ignored for the convenience of one or more involved parties. The idiom also implies a value judgment that the issue should be discussed openly.

The idiom is commonly used in addiction recovery terminology to