在英语合成词中，有一种不是很普遍的，也较少人注意的，那就是叠声合成词(repetition compounds)。
叠声合成词多数是名词，也可转化为形容词、动词或副词，有三种形式：
Ⅰ两个字都相同，如：
●He pooh-poohed my idea.(轻视)
●It is a hush-hush report not to be made public.(秘密的)
●The boy said bye-bye to his parents.(再见)
其他类似的叠声合成词有：
clank-clank(链子声), drip-drip(雨水声), tap-tap(打字机的声音), so so(马马虎虎), goody-goody(伪善的), fifty-fifty(各半的), pretty-pretty(打扮得很俗气的), thump-thump(砰然声), snip-snip(剪声)等。
Ⅱ第二字的元音和第一字的不同，如：
●Electric networks criss-cross the whole island.(交叉往来)
●The government dilly-dallied over lengthening the retirement age.(犹疑不决)
●he blinds flip-flopped in the wind.(飘摇、摇曳)
●The drunkard zig-zagged along the road.(弯弯曲曲地走)
●Most women like knick-knacks.(小装饰品)
●Is it possible to get rid of the riff-raff of a society?(下等人)
●The graduating students had a pleasant sing-song in the garden.(歌唱会)
●Do you like wishy-washy soup?(淡而无味的)
Ⅲ第二字的辅音和第一字的不同，如：
●Barbarians in ancient times had to kow-tow to government officials.(叩头)
●Some people are not used to the hub-bub of the city. (喧嚣)
●I pity those who lead a humdrum life year in year out.(单调的)
