clearance

名词 clearance:

1. the distance by which one thing clears another; the space between them
2. vertical space available to allow easy passage under something
   同义词：headroom, headway
3. permission to proceed

1. Let me tell you some details about clearance.
   让我告诉你一些通关的细节。

clear.ance

n.（名词）
The act or process of clearing.
清洁，清扫：清洁的行为或过程
A space cleared; a clearing.
清理过的空间；清光林木的空旷地
Abbr. cl.
缩写 cl.
The amount of space or distance by which a moving object clears something.
清除区域：移动物体其清除某物的空间或距离的大小
The height or width of a passage:
净空，余隙：通道的高度或宽度：
例句：
an underpass with a 3-foot clearance.
有3英尺净空的高架桥下通道

An intervening space or distance allowing free play, as between machine parts.
空隙，间隙：允许自由运动所介入的空间或距离，如在机器零件之间的
Permission for an aircraft, ship, or other vehicle to proceed, as after an inspection of equipment or cargo or during certain traffic conditions.
结关，准许通行：让飞机、轮船或其它交通运输工具继续前进的许可，如经过对设备和货物的检查或在特定的交通状况下
Official certification of blamelessness, trustworthiness, or suitability.
证明书：无过失、可靠或称职的官方证明
A sale, generally at reduced prices, to dispose of old merchandise.
清仓大拍卖：处理旧货的销售，通常减低价格
Abbr. cl.The passage of checks and other bills of exchange through a clearing-house.
缩写 cl.票据交换：通过票据交换所的支票传递或其它帐单的交换
Physiology
【生理学】
The removal by the kidneys of a substance from blood plasma.
清除：肾将血浆中一种物质的移出
Renal clearance.
肾清除