Pronunciation: [at klˈə͡ʊs] (IPA) 
The spelling of the phrase "at close" can be quite confusing. The "a" in "at" is pronounced as /æ/ while the "o" in "close" is pronounced as /oʊ/. This leads to the confusion of whether to spell it as "at close" or "at cloze". However, the correct spelling is "at close" because the "o" sound in "close" is a diphthong, which means it is made up of two vowel sounds. Therefore, it is pronounced as /kloʊz/ and not /kloz/.
The term "at close" is a phrase commonly used to refer to the end or conclusion of a particular event, activity, or time period. It signifies the point at which something is ending, often denoting the completion of a task, a business day, a process, or any other specific period of time.
In business contexts, "at close" typically refers to the end of a trading day in the financial markets, when the trading session concludes. It signifies the moment when the market stops operating and transactions are no longer executed. At close, the final price at which a security is traded is often established and recorded for the day.
Furthermore, "at close" is also employed to describe the completion of a transaction or deal. For instance, a sales agreement may state that a purchase must be made "at close," indicating that the transaction is required to be finalized by the end of a specific time period, such as the end of the business day or before the close of business.
Overall, "at close" is a concise and widely understood phrase that signifies the conclusion or termination of a particular event, activity, or period of time, commonly used in financial and business contexts.
The term "at close" is not a common phrase in English. It could have multiple interpretations depending on the context. However, if you are referring to the phrase "at close quarters", its etymology can be traced as follows:
Etymologically, "close" in this sense comes from the Old French word "clos", meaning "enclosed" or "confined". The term "at close quarters" was originally used in military contexts and referred to combat that takes place at short distances where individuals are near or in close contact with each other. Over time, the phrase extended its meaning to situations that involve proximity or intimacy, not limited to military scenarios.
