The idiom "shadowban" refers to the practice of banning or removing a user's posts from a social media platform without notifying them.

The idiom "old hat" refers to something that is outdated, worn-out, or no longer relevant, often in a figurative sense. It can also refer to someone who is old-fashioned or traditional in their views or behavior.

The idiom "ward off" means to keep something away or prevent it from happening. It can also mean to protect oneself from danger or harm. The figurative meaning of the idiom is often used to describe a situation where someone or something is being kept at bay or excluded.

The idiom "ring a bell" means to remind someone of something or to call attention to an event, typically by making a sound like a bell ringing. It can also mean to be impressed or affected by something, or to signal the end of something.

The idiom "out of the blue" means something happens suddenly, unexpectedly, or without any warning. It can also mean that an event is surprising or shocking.