1. 表示时间：过去的一段时间（时期），曾经，一度，过去;过去……曾
Criminals could at one time be sentenced to penal servitude.
曾经有个时期，罪犯可以被判服劳役刑。
At one time, walking across the room took all her strength
曾经有段时间她得费尽全力才能从房间一头走到另一头。
At one time the schools were mainly attached to the church.
这些学校曾一度归教会主管。
At one time 400 men, women and children lived in the village.
曾经有400个男人、女人和孩子居住在村子里。
At one time, Shenzhen was a small village.
深圳曾经是一个小村庄。
At one time, soap-making was not safe.
曾经,肥皂制造是不安全的。
At one time, high-grade cosmetics were the popular items on the market.
高档化妆品在市场上一度很抢手。
At one time people thought that Minnesota was not a good place to live in.
过去人们曾认为明尼苏达州不是居住的好地方。
At one time, this city was a bustling center of trade.
曾经，这座城市是一个繁华的贸易中心。
At one time, this company dominated the market, but now it faces tough competition.
曾经，这家公司主导了市场，但现在面临激烈的竞争。
All of them were French possessions at one time or another.
它们都曾是法国的领地。
All of these industries have at one time or another been linked to cancer.
所有这些产业都曾在不同时期与癌症有过联系。
Everyone has taken a not-so-great class at one time or another ．
每个人都曾上过一次不太好的课。
高考真题- 2019 全国3卷 七选五
2.表示频次：每一次，一次
The fish lay thousands of eggs at one time.
这种鱼一次产卵数千个。
It would have been better to have thinned the trees over several winters rather than all at one time
当初要是分几个冬天疏剪树木，会比一下子疏剪完效果好。
Members can borrow up to ten books from the library at any one time.
会员在图书馆每次最多可借十本书。
Do you like to have many projects on the go at any one time?
你喜欢一次忙多个项目吗？
Only one-half of the attendees could fit into the large hall at any one time.
这个大厅一次只能容下一半的出席者。
注意：
one-time friend以前的朋友，曾经的朋友
one-time mayor前市长，
this one-time doctor则表示这个人过去做过医生；以前做过医生的人
her one-time best friend, Anna
她以前的挚友安娜
The charity is still feeling the effects of revelations about its one-time president
这家慈善机构仍受到其前主席被检举带来的影响。
She's 87 years old, and a one-time member of the Ziegfeld Follies
她现年87岁，曾经是齐格菲尔时事讽刺剧团的成员之一。
His one-time admirers now accuse him of being a turncoat.
曾经一度仰慕他的人如今指责他是叛徒。
另一个含义是：一次性全包的。相当于one-off
a one-time fee of $500
500元的一次性总费用
a one-off payment一次性付款
Interest is calculated daily and credited once a year, on 1 April.
利息按天计算，每年4月1日一次性打入账户。
形容物品只能使用一次，则用disposable（用完即可丢弃的）：
disposable gloves/razors
一次性手套 / 剃刀
disposable nappies
一次性尿布
disposable diapers
一次性尿布
daily disposable contact lenses
日用型一次性隐形眼镜；
disposable slippers一次性拖鞋；
disposable cup一次性纸杯
但是：disposable income可支配（税后）收入
Gerald had little disposable income.
杰拉尔德的可支配收入很少。
The nation's disposable earnings in 1987 amounted to £ 86 billion.
1987年国民可自由支配收入达到了860亿英镑。
reusable可重复使用的
I prefer disposable masks to reusable masks.
相比可重复使用的口罩，我更喜欢一次性口罩。
Many people are switching to reusable shopping bags instead of relying on disposable plastic bags.
很多人正在转向可重复使用的购物袋，而不是依赖一次性塑料袋。
He shaved himself with a disposable razor.
他用一次性刀片刮脸。
Disposable nappies are fairly straightforward to put on
一次性尿布很容易穿上。
Companies produce thousands of different kinds of disposable products: paper plates, plastic cups, and cameras, to name a few.
公司生产成千上万种一次性产品：纸盘、塑料杯和照相机等等。
高考真题- 2015 安徽 完形填空
We bought disposable plates and utensils for the picnic to make clean-up easier.
我们为野餐购买了一次性餐盘和餐具，以便清理更方便。
The hospital provides disposable gloves for the staff to maintain hygiene protocols.
医院为员工提供一次性手套，以维护卫生协议。
Please make sure to properly dispose of your disposable coffee cup after use.
请确保使用后正确地处理你的一次性咖啡杯。
The airline offers passengers disposable headphones for their in-flight entertainment.
该航空公司为乘客提供一次性耳机，供他们在飞行中使用娱乐设备。
We live in a throwaway society. 我们生活在一次性物品充斥的社会。
Now they are producing throwaway razors. 他们正在生产一次性剃须刀。
There seems to be little difference whether you eat all your calorie allowance in one go, or spread it over the day
不管你是一次性摄入全天的卡路里限量，还是在一天内分次摄入，结果好像没有多大差别。