Old English understandan "comprehend, grasp the idea of", probably literally "stand in the midst of", from under + standan "to stand" (see stand (v.)). If this is the meaning, the under is not the usual word meaning "beneath", but from Old English under, from PIE *nter- "between, among" (cognates: Sanskrit antar "among, between", Latin inter "between, among", Greek entera "intestines"; see inter-). Related: Understood; understanding.
翻译过来就是:古英语understand"理解,掌握的想法,"大概字面意思是"站在中间,"是从下面+ standan"站"(见stand (v.))。如果这就是它的意思,那么"under"就不是通常意义上的"下面",而是源自古英语"under",源自PIE *"nter——between, among"(同根词:梵语"antaramong, between","拉丁语inter,between","希腊语entera")。相关:understood; understanding.
看了understand词源后,大家好像已经了解了"understand"中的under,不是"在……下面"的意思,而是表示"在……之间",但对于"understand"本身还是不太理解。这跟"理解"有什么关系?我们该怎么把"在……之间"和"理解"联系在一起?under是inter的古英语形态,后来首字母u演变为i,就变成了inter。介词inter-表示"在一起,交互"理解英语怎么说;有"在…中间、在…之间"的意思。"站在你中间",也就是站在你的位置上。啊!这不就是我们熟悉的成语"设身处地"嘛!"设身处地"——设想自己处在别人的境地,站在别人的处境替别人着想。这样,"understand" 就代表着"我站在你中间,我站在你的思想中间,"也就是"我理解你了"。