channel:  Channel and canal are ultimately the same word. Their common ancestor was Latin canālis ‘groove, channel’, a derivative of canna ‘pipe’ (source of English cane). This passed into Old French as chanel, which English took over as channel. But then in the 15th century English acquired canal, either directly from Latin, or from French canal, which was itself remodelled on the Latin form – it is not clear which. => canal, cane
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.