水素

A school term or semester that divides the academic year into specific periods of study. In Japan, the academic year is typically divided into three terms starting in April, September, and January.

期限 refers to a time limit, deadline, or expiration date by which a specific action must be completed or a period ends. It is commonly used for business deadlines, document submissions, and the shelf life of food products.

A specific moment in time or a point in time, often used to describe the ticking passage of time. Historically, it also refers to a specific unit of time (roughly two hours) in the traditional Japanese timekeeping system.

A Buddhist-derived term referring to an extremely short period of time, similar to an 'instant' or 'moment.' It often carries a poetic or philosophical nuance, suggesting that something is fleeting or transient.

Refers to a state of lasting forever or being permanent without change. It is often used to describe time, systems, or physical states that are intended to remain indefinitely.

This word refers to a state of being eternal or lasting forever without an end. It is commonly used in emotional, philosophical, or romantic contexts to describe things that do not change over time.

A formal term referring to a short period of time or a brief moment. It is typically used in writing or polite speech to describe a temporary state or a short duration of an action.

A phrase used to express that a significant amount of time has passed since an event last occurred or since meeting someone. It is most commonly used as a greeting equivalent to 'Long time no see' in English.

晩期 refers to the final or late stage of a specific period, process, or condition. It is most commonly used in historical, archaeological, or medical contexts to describe the concluding phase of an era or the advanced stage of a disease.

The first stage or beginning period of an event, process, or historical era. It is used to describe the initial phase of something that continues over time.