The idiom "a black sheep" refers to someone in a family or group who is considered different, problematic, or disreputable compared to others. This phrase often carries a negative connotation, suggesting that the individual does not conform to the norms or expectations of the group, thereby standing out in a way that is often undesirable.

The idiom "to play second fiddle" means to take a less important or subordinate role compared to someone else. It originates from orchestral music, where the second fiddle (or violin) plays a supporting role to the first fiddle. This phrase is often used to describe situations in which someone is in a secondary position, either in work or relationships.

The idiom "to pick holes" means to criticize or find faults in an argument, plan, or piece of work. It suggests a detailed examination where someone identifies weaknesses or problems, often to undermine the validity of the original work or idea.

The idiom "above board" refers to actions that are transparent, honest, and without deceit. It implies that everything is conducted openly, with no hidden agendas or dishonest practices. The phrase is often used in contexts involving business or ethical considerations to indicate integrity in conduct.

The idiom "tickled pink" means to be extremely happy or delighted about something. It conveys a sense of joy and satisfaction, often in response to a pleasant surprise or good news. The phrase evokes a lighthearted and cheerful feeling.

The idiom "end in smoke" means that a plan or endeavor ultimately fails or comes to nothing, often after much effort. It evokes the image of something that dissipates like smoke, highlighting the idea that despite the hopes or expectations, the outcome was unsatisfactory or wasted.

The idiom "to grease the palm" refers to giving someone money or a gift, typically as a bribe, to ensure favorable treatment or to persuade them to act in a certain way. It suggests an unethical exchange, where the intention is to gain an advantage through financial incentives.

The idiom "cry wolf" comes from the fable about a shepherd boy who falsely claimed a wolf was attacking his flock. When the wolf actually appeared, no one believed him. Thus, the phrase refers to situations where someone raises false alarms or cries for help when it isn't warranted, leading to a loss of credibility when a real issue arises.

The idiom "to catch a tartar" refers to getting involved with someone or something that proves to be much more challenging than anticipated. The phrase originates from the notion of encountering a Tartar, a fierce warrior group, indicating that what seemed easy might actually be quite formidable.

An "armchair critic" is someone who offers opinions and judgments about a subject—often in the context of art, sports, or politics—without having firsthand experience or involvement in it. This term suggests a level of detachment and a lack of real-world engagement in the matters they are critiquing.