CalaisyoudaoicibaDictYouDict[Calais 词源字典]
city on the French coast of the English Channel, from Gaulish Caleti, the name of a Celtic people who once lived along the shore there.[Calais etymology, Calais origin, 英语词源]
channel (n.)youdaoicibaDictYouDict
early 14c., "bed of running water," from Old French chanel "bed of a waterway; tube, pipe, gutter," from Latin canalis "groove, channel, waterpipe" (see canal). Given a broader, figurative sense 1530s (of information, commerce, etc.); meaning "circuit for telegraph communication" (1848) probably led to that of "band of frequency for radio or TV signals" (1928).

English Channel is from 1825; the older name was British Channel (by 1730). John of Trevisa's Middle English translation of the encyclopedia De Proprietatibus Rerum (c. 1398) has frensshe see for "English Channel." The Channel Islands are the French Îles Anglo-Normandes.
sleeve (n.)youdaoicibaDictYouDict
Old English sliefe (West Saxon), slefe (Mercian) "arm-covering part of a garment," probably literally "that into which the arm slips," from Proto-Germanic *slaubjon (cognates: Middle Low German sloven "to dress carelessly," Old High German sloufen "to put on or off"). Related to Old English slefan, sliefan "to slip on (clothes)" and slupan "to slip, glide," from PIE root *sleubh- "to slide, slip."

Compare slipper, Old English slefescoh "slipper," slip (n.2) "woman's garment," and expression slip into "dress in." Mechanical sense is attested from 1864. Meaning "the English Channel" translates French La Manche. To have something up one's sleeve is recorded from c. 1500 (large sleeves formerly doubled as pockets). To wear one's heart on (one's) sleeve is from "Othello" (1604).
south (adv.)youdaoicibaDictYouDict
Old English suð "southward, to the south, southern, in the south," from Proto-Germanic *sunthaz, perhaps literally "sun-side" (cognates: Old Saxon, Old Frisian suth "southward, in the south," Middle Dutch suut, Dutch zuid, German Süden), and related to base of *sunnon "sun" (see sun (v.)). Old French sur, sud (French sud), Spanish sur, sud are loan-words from Germanic, perhaps from Old Norse suðr.

As an adjective from c. 1300; as a noun, "one of the four cardinal points," also "southern region of a country," both late 13c. The Southern states of the U.S. have been collectively called The South since 1779 (in early use this often referred only to Georgia and South Carolina). South country in Britain means the part below the Tweed, in England the part below the Wash, and in Scotland the part below the Forth. South Sea meant "the Mediterranean" (late 14c.) and "the English Channel" (early 15c.) before it came to mean (in plural) "the South Pacific Ocean" (1520s). The nautical coat called a sou'wester (1836) protects the wearer against severe weather, such as a gale out of the southwest.