sinkyoudaoicibaDictYouDict[sink 词源字典]
sink: [OE] Sink is a general Germanic verb, with relatives in German sinken, Dutch zinken, Swedish sjunka, and Danish synke. But where their common Germanic ancestor came from is not known. These days, sink means both ‘go below water’ and ‘cause to go below water’, but originally it was used only for the former. There was a separate but closely related verb, sench, for ‘cause to sink’, which died out in the 14th century. The noun sink [15] originally denoted a pit ‘sunk’ in the ground for receiving water.
[sink etymology, sink origin, 英语词源]
sink (v.)youdaoicibaDictYouDict
Old English sincan (intransitive) "become submerged, go under, subside" (past tense sanc, past participle suncen), from Proto-Germanic *senkwan (cognates: Old Saxon sinkan, Old Norse sökkva, Middle Dutch sinken, Dutch zinken, Old High German sinkan, German sinken, Gothic sigqan), from PIE root *sengw- "to sink."

The transitive use (mid-13c.) supplanted Middle English sench (compare drink/drench) which died out 14c. Related: Sank; sunk; sinking. Sinking fund is from 1724. Adjective phrase sink or swim is from 1660s. To sink without a trace is World War I military jargon, translating German spurlos versenkt.
sink (n.)youdaoicibaDictYouDict
early 15c., "cesspool, pit for reception of wastewater or sewage," from sink (v.). Figurative sense of "place where corruption and vice abound" is from 1520s. Meaning "drain for carrying water to a sink" is from late 15c. Sense of "shallow basin (especially in a kitchen) with a drainpipe for carrying off dirty water" first recorded 1560s. In science and technical use, "place where heat or other energy is removed from a system" (opposite of source), from 1855.