adv.(副词)

1. 以前
2. 事先
3. 不成熟地
4. 仓促地
5. 上面
6. 曾经是
7. 已经...过的
8. 先前地（在时间或顺序上存在或发生在其它别的事之前地）
9. 过去

Adverb:

1. at an earlier time or formerly;

   "she had previously lived in Chicago"
   "he was previously president of a bank"
   "better than anything previously proposed"
   "a previously unquestioned attitude"
   "antecedently arranged"
   

1.先前；以前
previously means at some time before the period that you are talking about.

previously

e.g. Guyana's railways werepreviously owned by private companies...
圭亚那的铁路以前是归私有企业所有的。
e.g. The contract was awarded to apreviously unknown company...
合同签给了一个之前并不知名的公司。

2.（一段时间）以前
You can usepreviously to say how much earlier one event was than another event.

e.g. He had first entered the House 12 yearspreviously...
12年前，他首次成为议员。
e.g. She had rented the flat from the council some fourteen monthspreviously.
大约14个月以前，她从地方政府那里租下了这套公寓。

If you are talking about a period measured back from some earlier time, you usebefore orpreviously.He had died a month before…She had rented the flat some fourteen months previously. You only useago when you are talking about a period of time measured back from the present. You usefor to say how long a period lasts in the past, present, or future, or how much time passes without something happening.She slept for eight hours… He will be away for three weeks… I hadn't seen him for four years. You usesince to say when a period of time started.She has been with the group since it began. …the first civilian president since the coup 17 years ago. You also usesince to refer to the last time that something happened, or to how much time passes without something happening.She hadn't eaten since breakfast… It was a long time since she had been to church.
如果谈论过去某个时间以前的时间，用 before 或者 previously：He had died a month before（他一个月前去世了），She had rented the flat some fourteen months previously（她大约14个月以前租下了这套公寓）。ago仅用于谈论现在之前的某段时间。for用来表示过去、现在或将来持续的一段时间或者某事多长时间没有发生，如：She slept for eight hours（她睡了8个小时），He will be away for three weeks（他会离开3个星期），I hadn't seen him for four years（我已经有4年没有见过他了）。since用来表示某段时间的开始，如：She has been with the group since it began（自从该集团创立起她就一直在其中工作），the first civilian president since the coup 17 years ago（自从17年前发生政变以来的第一位平民总统），since也可以用来某事最后一次发生的时间或者某事多长时间没有发生，如：She hadn't eaten since breakfast（她早餐以后就没吃过东西），It was a long time since she had been to church（她好久没去过教堂了）。

1.

1. 在以前：pressesctoexit 敲键退出 |previously 在以前 | printall 全部打印

2. 以前：previously designated 预先指定的 |previously 以前 |previously 在前

3. 在前：previously 以前 |previously 在前 | prewar 战前

4. 先前：previous 前一个 |previously 先前 | previse 预知

The device had been used operationally some months previously.

该设备几个月之前曾投入运行。

He may suddenly take a dislike to foods that he's previously enjoyed.

对以前爱吃的食物，他兴许突然就没了胃口。

He had first entered the House 12 years previously.

12年前，他首次成为议员。

The changed outlook entails higher economic growth than was previously assumed.

观念的改变势必会使得经济增长高于之前预计的水平。

The two fighters had previously boxed a 12-round match.

这两位拳击手之前已经打了一场12回合的比赛。

Reviews are distilled from articles previously published in the main column.

述评是从先前刊登在主要专栏的文章中提炼出来的。

Radiation may damage cells in a way that was previously unforeseen.

辐射可能以一种我们过去未能预见到的方式破坏细胞。

Spassky had never previously lost to his antagonist.

斯帕斯基以往从未输给过他的对手。

deviation from the previously accepted norms

违背事先接受的准则

a previously undiscovered talent

以前没被发掘的天才

a species of insect previously unknown to science

科学上以前尚未了解的一种昆虫

Let me digress for a moment and explain what had happened previously.

让我岔开一会儿,解释原先发生了什么.

The bicycle tyre blew out at a previously damaged point.

自行车胎在以前损坏过的地方又爆开了.

The previously unidentified objects have now been definitely ascertained as being satellites.

原来所说的不明飞行物现在已证实是卫星.

previously our mountain area [ region ] is poor and impoverised.

先前咱们 山区 很穷.

• previous以前的
• previously%20stored%20file">previously stored file先前存储文件...
• previously%20stored%20data">previously stored data先前存储数据...

• The fiddlers were doing the up bow-stroke previously to..the opening chord.

  出自：T. Hardy

• A despair greater than any she had previously felt.

  出自：L. Appignanesi