To remove from a trench; to emerge from a fortified position, or to dislodge something from entrenched positions.
From de- (off/away) + trench. A military term formed analogously to 'entrench,' but much rarer. Appears occasionally in military historical writing.
Detrench is the kind of specialized military vocabulary that sounds plausible because English allows these formations (like detrain), but it's rarely used because other terms like 'dislodge' or 'withdraw' convey the meaning more naturally.
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