来源于古英语，亦可以当词根讲,这个前缀的引申意思是：继，隔山，后父或后母所生的，前妻或前夫所生的。

词缀扩展：宇宙形成后生命才开始出现：universe- / cosmo- 宇宙，它们分别来源于拉丁语 universum 和希腊语，如：universal 普通，通用的、cosmos 宇宙。

词源：

Old English steop-, with connotations of "loss," in combinations like steopcild "orphan," related to astiepan, bestiepan "to bereave, to deprive of parents or children," from Proto-Germanic *steupa- "bereft" (cognates: Old Frisian stiap-, Old Norse stjup-, Swedish styv-, Middle Low German stef-, Dutch stief-, Old High German stiof-, German stief-), literally "pushed out," from PIE *steup-, from root *(s)teu- (1) "to push, stick, knock," with derivatives referring to fragments (see steep (adj.)). Barnhart suggests the forms in -f- are by assimilation of the first sound in following words for "father."

Etymologically, a stepfather or stepmother is one who becomes father or mother to an orphan, but the notion of orphanage faded in 20c. and came to denote simply relation through marriage. For sense evolution, compare Latin privignus "stepson," related to privus "deprived." Compare orphan (n.).

同缀词：

1.stepfather [step- + father]
n.后父,继父

2.stepmother [step- + mother]
n.后母,继母

3.stepson [step- + son]
n.前妻 ( 或前夫 ) 之子

4.stepdaughter [step- + daughter]
n.前妻 ( 或前夫 ) 之女