在常用词absent和abstract中含有一个拉丁语源的原生词缀 ab- (abs- )。它原是拉丁介副词，意思相当于英语的away from或 off。这个前缀一般加在拉丁词根上，构成动词及相应的形容词与名词。abs-是ab-的异体，出现在以c, t开头的词根前。ab- (abs- )是个僵化词缀，我们下面分析的都是原生派生词。

先介绍几个常见的含有(abs-)的单词。

absent [ab- = away 离;sent = to be 是→]I a . being away; not present 不在；缺席 / He is absent from class today.他今天缺课。 

II v. keep (oneself) away 缺席，不到 / Try not to absent yourself more than necessary.尽量不要无故缺席。

absentee n. 不在者，缺席者 

absence n. 不在，缺席

absorb [ ab- = away 离;sorb = to suck in 吸人=>“to suck in sth. away from 从…吸人某物” →] take in 吸收 / Sponges absorb water. 海绵吸水。

absorbable a .可吸收的

abstract [ abs- ( ab-) = away 离；tract = to draw 抽=> “ to draw away 抽离，抽取”→] v . take away; remove 提取；分离 / Iron is abstracted from ore.铁是从铁矿石中提炼出来的。

abstraction n. 提取;分离

abscond [ abs- ( ab-) = away 离；cond = to store 贮藏=>“to store away 藏匿起来”→]v . go off and hide 潜逃/The dishonest cashier absconded with the bank’s money. 心术不正的银行出纳员携款潜逃。