officially [əˈfɪʃəlɪ]

Officially is an adverb that means something is done or recognized by an authority, government, or organization. It can also mean something is done according to the rules or regulations set by a particular institution.

用法：

Officially is used to describe something that has been formally approved, recognized, or announced by an authoritative source. It can also be used to describe something that has been done in accordance with established rules or procedures.

例句：

1. The new policy was officially announced by the company's CEO.

新已经被公司CEO正式宣布。

2. The government officially recognized the country's independence.

正式承认该国的独立地位。

3. The team was officially declared the winner of the tournament.

该队正式被宣布为锦标赛的获胜者。

4. The concert was officially sold out within minutes of tickets going on sale.

门票一开售，演唱会就在几分钟内被宣布售罄。

5. The movie has not been officially released yet, but it has already received rave reviews from critics.

电影还没有正式上映，但已经收到了评论家的好评。

同义词及用法：

1. Formally - This adverb has a similar meaning to officially and can be used interchangeably in most cases. However, formally may also imply a sense of ceremony or tradition.

2. Legitimately - This adverb means something is done in accordance with established laws or principles and can be used as a synonym for officially in certain contexts.

3. Authoritatively - This adverb means something is done with authority and can be used to describe an official action or statement.

4. Validly - This adverb means something is done with legal or moral authority and can be used to describe an official decision or action.

5. Properly - This adverb means something is done in the correct or appropriate manner and can be used to describe an official procedure or announcement.

编辑总结：

Officially is a versatile adverb that is commonly used to describe something that has been formally approved, recognized, or announced by an authoritative source. It can also be used to describe something that has been done in accordance with established rules or procedures. When writing, it is important to use this word accurately and appropriately in order to convey the intended meaning. Additionally, using synonyms such as formally, legitimately, authoritatively, validly, and properly can add variety and depth to your writing.