rook 2 (rk)
n. Abbr. R
A chess piece that may move in a straight line over any number of empty squares in a rank or file. Also called castle.
[Middle English, from Old French roc, from Arabic ruḫḫ, from Persian ruḫ, from Middle Persian rox, ultimately from Middle Indic rahu, raho, nominative of raha- raha-, chariot, from Prakrit ratha-, from Sanskrit rathaḥ (the original form of the rook in the early chess of India being a chariot); see ret- in the Appendix of Indo-European roots.]
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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.