In ancient times the iron-and-wood cangue was an instrument of interrogation.
Tips
history
Xinhua's older sense of 铁木 is collective — 'instruments of iron and wood,' i.e. fetters and cangues used for punishment in imperial China. The modern botanical sense (the genus Ostrya / hopbeam, sometimes Mesua) is a 20th-century reuse for any tree whose wood is hard as iron.
culture
铁木 is also the Chinese rendering of Temür (Mongolian 'iron'), part of names like 铁木真 (Tiěmùzhēn, the birth name of Genghis Khan) and 帖木儿 (Tiēmù'ér, Tamerlane). Context decides whether it's the wood or a Mongol/Turkic name fragment.
