auger (n.)youdaoicibaDictYouDict[auger 词源字典]
c. 1500, faulty separation of Middle English a nauger, from Old English nafogar "nave drill," from Proto-Germanic *nabo-gaizaz (cognates: Old Norse nafarr, Old Saxon nabuger, Old High German nabuger), a compound whose first element is related to nave (n.2) and whose second is identical to Old English gar "a spear, borer" (see gar). For similar misdivisions, see adder. The same change took place in Dutch (avegaar).[auger etymology, auger origin, 英语词源]
nave (n.2)youdaoicibaDictYouDict
"hub of a wheel," Old English nafu, from Proto-Germanic *nabo- (cognates: Old Saxon naba, Old Norse nöf, Middle Dutch nave, Dutch naaf, Old High German naba, German Nabe), perhaps connected with the root of navel on notion of centrality (compare Latin umbilicus "navel," also "the end of a roller of a scroll," Greek omphalos "navel," also "the boss of a shield").
overt (adj.)youdaoicibaDictYouDict
early 14c., "open to view," from Old French overt (Modern French ouvert), past participle of ovrir "to open," from Latin aperire "to open, uncover," from PIE compound *ap-wer-yo- from *ap- "off, away" (see abo-) + base *wer- (5) "to cover" (see weir). Compare Latin operire "to cover," from the same root with PIE prefix *op- "over;" and Lithuanian atveriu "open," uzveriu "shut."