1.official用作名词的意思是“文职官员,公务员”,特别指在政府、银行各部门及工会里的工作人员。
2.official可用作可数名词,也可用作不可数名词。

She accused the official of corruption.她指控那位官员腐败。
The man with glasses is a high official.那个戴眼镜的人是一位高级官员。
The President and the Secretary of State are government officials.总统和国务卿是政府官员。
The measure will mainly be carried out by government officials.这项措施主要由政府官员来执行。

他的叔父过去是部队里的一个高级军官。
［误］  His uncle was formerly a high-ranking official in the army.
［正］  His uncle was formerly a high-ranking officer in the army.
［析］  部队里的军官一般用officer。

official用作形容词的意思是“公务的,职务的,官方的,正式的”,不带感情色彩,在句中多用作定语,间或可用作表语,没有比较级与最高级形式。

用作定语
▲～+n.
His official duties kept him busy.公务使他繁忙不堪。
The official announcement was made a day or two later.一两天后官方发表了公告。
The President wanted to make an official visit to the country.这位总统希望对那个国家进行正式访问。
用作表语
▲S+be+～
This statement is official and binding on both sides.这声明是正式的,对双方都具有约束力。
The news is almost certainly true although it is not official.尽管消息是非官方的,但是几乎确凿无疑。

official, officious
这两个词词形相近,但意义不同。在外交上, official指“官方的”,而officious则与其相反,指“非官方的”; 在日常用语中, official不带感情色彩,而officious带贬义,指“好管闲事的”“过分殷勤的”。例如:
An officious little guard came and told me not to whistle in the museum garden.一位爱管闲事的小警卫走过来叫我不要在博物馆花园里吹口哨。

［同义词］ adj.  administrative, formal, licensed
［反义词］ adj. unauthorized, unofficial