spanking (adj.)youdaoicibaDictYouDict[spanking 词源字典]
1660s, "very big or fine," later (especially of horses) "moving at a lively pace" (1738), of uncertain origin; perhaps from a Scandinavian source (OED compares Danish spanke "to strut"). Probably also related to spanker "something striking" (for size, etc.), 1751; as a kind of sail from 1794.[spanking etymology, spanking origin, 英语词源]
spanking (n.)youdaoicibaDictYouDict
"act of striking with the open hand," especially as a punishment administered to children, 1854, verbal noun from spank (v.).