The idiom "saved by the bell" means that a person is rescued or liberated from a difficult situation just before it becomes too hopeless or disastrous. This phrase often implies a sudden change of fortune, and can be used to describe a variety of circumstances.

"Spanner in the works" is an idiom that means a sudden and unexpected event or occurrence that disrupts or hinders a planned or ongoing activity. The figurative meaning of this idiom is that it can cause chaos, confusion, or frustration in the workplace or in personal relationships.

The idiom "know the ropes" means to have a thorough understanding or knowledge of something, especially in regards to its procedures, practices, or ways of doing things. It can also refer to being familiar with a certain situation or set of circumstances.

The idiom "hold tongue" means to keep quiet, refrain from speaking, or not say something that may upset someone. It is a way of suppressing one's thoughts or emotions to avoid causing harm or discomfort to others.

The idiom "turn the clock back" means to go back to a previous, better or more enjoyable time. It can also refer to reversing a negative situation or undoing a mistake. In a metaphorical sense, it means revisiting a past moment and reliving it, often with nostalgia.