lacuna (n.)youdaoicibaDictYouDict[lacuna 词源字典]
"blank or missing portion in a manuscript," 1660s, from Latin lacuna "hole, pit," diminutive of lacus "pond, lake" (see lake (n.1)). The Latin plural is lacunae. Related: Lacunal; lacunar; lacunose.[lacuna etymology, lacuna origin, 英语词源]