clanyoudaoicibaDictYouDict[clan 词源字典]
clan: [14] The immediate source of clan is naturally enough Gaelic, but ultimately it comes, somewhat unexpectedly, from Latin, for etymologically it is the same word as plant. Scots Gaelic clann originally meant ‘offspring’ (hence the modern meaning ‘family group’), and it came from Old Irish cland, a direct borrowing from Latin planta (the Celtic languages of the British Isles tended to change Latin /p/ to /k/).

This was the source of English plant, but it did not then have nearly such a broad application; it meant specifically ‘shoot suitable for planting out’, and the connotations of ‘new growth’ and ‘offspring’ show up in the Gaelic borrowing.
=> plant[clan etymology, clan origin, 英语词源]
clan (n.)youdaoicibaDictYouDict
early 15c., from Gaelic clann "family, stock, offspring," akin to Old Irish cland "offspring, tribe," both from Latin planta "offshoot" (see plant (n.)). The Goidelic branch of Celtic (including Gaelic) had no initial p-, so it substituted k- or c- for Latin p-. The same Latin word in (non-Goidelic) Middle Welsh became plant "children."