opposite用作名词时意思是“对立面,对立物,相反的人或事物”,是可数名词,通常与of连用。

The chief of the group has gone over to the opposite.那个组织的头头归降了对方。
I thought she would be small and pretty but she's completely the opposite.我以为她娇小而漂亮,结果完全相反。
He and I are the opposite of one another.我和他是彼此相反的两个人。

［同义词］ adj.  adverse, contrary, contrasted, different n.  contrary, converse
［反义词］ adj.  alike, similar n.  same

1.opposite可指空间位置上的“对面的”,也可指两件东西被认为位于一直线的两端,在地位、性质、意义等方面“对立”或“相反”。
2.opposite用作定语时,主要指空间位置上的关系,作“对面的”解,可前置,也可后置。前置时表示一对相对的物体或事物中的一个,两者有相互依存的关系,这种关系是客观的,永久的; 而后置时则表示暂时的空间关系或在讲话人或被谈论的人的对面。opposite作“相反的”解时可作前置定语,也可作表语。
3.opposite无比较级和最高级。

用作定语
▲～+n.
He cried to his friend on the opposite side of the street.他朝马路对面的一位朋友大声呼唤。
These are the opposite sides of the parallelogram.这是平行四边形的对边。
He hurried away in the opposite direction.他急忙朝相反的方向离去。
When he saw me coming he steered off in the opposite direction.他一看到我过来,掉头就走了。
She burst in through the opposite door.她从对面的那扇门冲进来。
The fireplace flamed up the opposite wall.炉光照亮了对面的墙壁。
The soldiers were arrayed on the opposite hill.士兵被部署在对面山上。
▲n.+～
Sad were the lights in the rooms opposite.对面房子里的灯光很暗淡。
“Can you see where the grammar books are?”“The dictionaries are on the shelf directly opposite.”“你看见语法书在哪儿吗?”“词典都在正对着的书架上。”
I found the child opposite looking at my red hat.我发现对面的孩子在看我的红帽子。
I asked the man opposite if he would open the door.我问对面的人他愿意不愿意开门。
He sat down on a sofa opposite to her.他在她对面的沙发上坐下。
He lives in the house opposite to ours.他住在我们对面的那栋房子里。
I took a seat opposite to her.我坐在她对面的席位上。
用作表语
▲S+be+～
Black and white are opposite.黑与白是截然相反的。
▲S+be+～ to n./pron.
Our house is opposite to theirs.我们的房子与他们的相对。
His political position is opposite to us.他的政治立场与我们相左。
The result was quite opposite to what we had expected.结果和我们所期望的完全相反。

opposite, contrary
这两个词的共同意思是“相反的”。其区别在于：
1.opposite指位置、方向、性质、意义等对立、相反,不一定有对抗的意味,强调分离。
2.contrary指“对立的”,常有对抗的含义,强调敌对矛盾和冲突。例如:
I am of a contrary opinion.我有相反的意见。

opposite用作副词时意思是“在对面”,在句中多用作状语。

用作状语
There's a couple with a dog who live opposite.对面住着一对夫妇,养着一条狗。
The woman sitting opposite is a detective.坐在对面的女子是个侦探。
I cannot stand opposite.我没法站在对面。
He sat opposite, doing nothing.他坐在对面什么也没干。