Out of bounds.

Out of bounds.
The expression 'out of bounds' originally comes from sports, where it refers to areas outside the play area where the ball is not permitted. By extension, this phrase now also metaphorically means an area or subject matter that is off-limits or forbidden. This could refer to physical locations you're not allowed to enter or topics that are considered inappropriate to discuss in certain social contexts. For instance, asking about someone's salary in a casual conversation is often considered 'out of bounds.'
Going beyond the fence is out of bounds.
Going beyond the fence is forbidden.
The restricted area is out of bounds for visitors.
The restricted area is off-limits for visitors.
Cheating on the exam is definitely out of bounds.
Cheating on the exam is completely unacceptable.
Break the ice" refers to actions taken to alleviate initial awkwardness and encourage more natural communication among people. Historically, this idiom comes from the day⋯ Read the full article
To "Blow off steam" is to release pent-up energy or alleviate stress through an activity or by expressing strong emotions. This idiom derives from the way steam engines r⋯ Read the full article
Back to square one" typically means returning to the starting point of a process or activity, often after a failed attempt or when a new approach is needed. This idiom is⋯ Read the full article
The idiom "At the drop of a hat" signifies doing something immediately, without any hesitation or delay. It comes from the 19th-century practice where dropping a hat coul⋯ Read the full article
Something that "Went down the drain" can refer to efforts, money, or time that has been wasted or lost, often irretrievably. This idiom paints a vivid picture of somethin⋯ Read the full article
To "Walk on eggshells" is to handle a situation with extreme care and caution, typically to avoid upsetting someone or triggering a negative response. This idiom is visua⋯ Read the full article
Being "Under the gun" means experiencing intense pressure to meet a deadline or to achieve a task within a limited time frame. This idiom originates from situations where⋯ Read the full article
The phrase "Time flies when having fun" highlights how subjective our perception of time can be, especially when we are engaged in enjoyable activities. This idiom is a r⋯ Read the full article
Through thick and thin" refers to being loyal and reliable under all circumstances, regardless of the difficulties or challenges that may arise. This idiom paints a pictu⋯ Read the full article
Take the cake" is an idiom used to indicate that something is the best or worst aspect of a situation. The phrase suggests taking away the top prize, like taking a cake a⋯ Read the full article
To "Sell like hot cakes" means to sell something very quickly and in large quantities, suggesting that the product is as desirable as freshly made hot cakes that everyone⋯ Read the full article
Run out of steam" metaphorically describes losing the energy or motivation to continue with an activity, much like a steam engine running out of steam and gradually comin⋯ Read the full article
Put foot down" refers to taking a firm, decisive action to stop something from happening. It evokes the image of physically stamping one’s foot to signify non-negotiable ⋯ Read the full article
To "Pull strings" means to use one’s influence or connections to obtain a favor or advantage that otherwise might not be possible. This idiom suggests the act of subtly m⋯ Read the full article
When something is a "Piece of cake," it means it is very easy to accomplish. This idiom is delightfully visual, comparing an easily achievable task to cutting a slice of ⋯ Read the full article