chestnut

The noun is a contraction of chest(en) (“(obsolete) chestnut tree; fruit of this tree, chestnut”) + nut. Chesten is a late variant of chesteine (obsolete), from Middle English chesten, chesteine, chasteine, chesteyne (“chestnut tree (Castanea sativa); fruit of this tree; wood of this tree”), from Old French chastaigne, chastaine (French châtaigne), from Latin castanea (“chestnut tree; fruit of this tree”) (whence Old English ċisten), from Ancient Greek κᾰστᾰ́νειᾰ (kăstắneiă), a variant of κᾰ́στᾰνᾰ (kắstănă, “sweet chestnut”); for further etymology, see that entry. Doublet of castanet. Noun sense 4 (“joke, phrase, etc., which has been repeated so often as to have grown ineffective or tiresome”) may refer to an 1816 play, The Broken Sword, by William Dimond (1781 – c. 1837), in which one character begins to relate a story in which a boy slips down from a cork tree, and another interrupts him to say that he had previously repeated the story many times, and always mentioned a chestnut tree. The adjective is probably from an attributive use of the noun; compare French (of hair) châtain (“chestnut”) (from châtaigne (“a chestnut”)) and marron (“brown”) (from marron (“a horse chestnut or chestnut”)).