在英语的合成词（compound words）中，合成动词（compound verbs）的数⽬较少，主要有下⾯三种类别：
㈠副词+动词，如 outdo, overcome, undermine, upt, cross-question, withhold, backbite 等。
otis ㈡名词+动词，如 sunbathe, sidetrack, typewrite, hou-hunt, browbeat, hoodwink, waylay 等。
诺拉琼斯好听的歌 ㈢形容词+动词，如 whitewash, safeguard, shortlist, blackmail 等。
expo是什么意思
这三类合成动词中，以第⼀种最为丰富，特别是那些由“over, under, out”引导的，更显得多彩多姿。
由 over 引导的合成动词含有“太多、过多”的意思，如： overact, overburden, overcharge, overdo, overdress, overeat, overestimate, overpower, overprai, overproduce, overprotect, overrule, oversleep, overspend, overstate, overstay, overwork 等。anthony davis
由 under 引导的合成动词含有“太少、不⾜”的意思，如： undercharge, underpay, underrate, understate, undervalue, underwork 等。
由 out 引导的合成动词则含有“超过、胜过”之意，如： outdo, outgrow, outlive, outnumber, outside, outrank, outshine, outstay, outstrip, outweigh, outwit 等。
现在举些句⼦⽰范：
① The food cost $3, but he was overcharged by 50 cents.
② Some romantic scenes in our TV shows were overdone.
③ Don't overstate your predicament or people will not believe you.
④ Some reporters understated the riousness of the regional financial turmoil.
⑤ The staff of the company felt that their contribution had been undervalued.
⑥ Chine swimmers outdid their opponents.
⑦ This type of computer has outlived its ufulness.
⑧ The advantages of the new salary scheme far outweigh its disadvantages.
最后，必须注意的是：不是凡是“over ”就是“过多、太多” ，凡是“under”就是“太少、不⾜”或凡是“out”就是“超过、胜过”。反之，有些合成动词根本和这⼏个副词的意思风马⽜不相及。例如：
● overhear（⽆意中听到）
● overlook（俯视、疏忽、忽略）
● overe（监督）
● overshadow（使……暗然失⾊）
nordost
● overthrow（*）
● overturn（使翻覆）
铃儿响叮当 英文 ● undergo（经历、遭受）
● underline（在……划线、强调）
● undermine（破坏）
● underpin（加强、巩固）
● understand（理解）
gre词汇量 ● understudy（充当替⼿）
gesture
● undertake（担任、着⼿）
moreorless ● outline（略述）
杀手信徒第二季 ● outrage（虐待，侵害）
● outspread（伸展）
