1. A traditional social unit in the Scottish Highlands, consisting of a number of families claiming a common ancestor and following the same hereditary chieftain.
2. A division of a tribe tracing descent from a common ancestor.
3. A large group of relatives, friends, or associates.
[Middle English, from Scottish Gaelic clann, family, from Old Irish cland, offspring, from Latin planta, plant, sprout; see plat- in the Appendix of Indo-European roots.]
Word History: The word clan is, from the etymological point of view, the same word as plant. Such a statement may at first appear unlikely to English speakers, since the two words begin with very different consonants. But to the speakers of the Celtic language of Ireland in the 400s, known as Old Irish, c and p sounded quite similar. When St. Patrick converted Ireland to Christianity in the 5th century, the Old Irish language had no consonant p. After their conversion, the Irish began to borrow many words from Latin, and when the speakers of early Old Irish tried to pronounce the sound p in Latin words, the best they could manage was a (kw) or (k) sound, spelled c in Old Irish. For instance, the Latin words purpura, "purple," and Pascha, "Easter," were borrowed as corcur and Casc. (Later, as their language continued to develop and change, the Irish learned to cope with p, and Modern Irish has many words containing this consonant.) The early Irish also borrowed the Latin word planta meaning "sprout" or "sprig,"—also the source of the English word plant—and pronounced it cland. In Old Irish, cland was used to mean not only "offshoot of a plant" but also "offspring," "family," and "clan." The word cland was carried to the area that is now Scotland when speakers of Old Irish gained power in the region in the late 400s. The form of Old Irish spoken in Scotland eventually developed into the language now known as Scottish Gaelic. In Scottish Gaelic, cland developed the form clann, and it was from Scottish Gaelic that the word clan entered English in the 15th century, at first with reference to the clans of the Scottish Highlands.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.