trenchant

The word trenchant comes from the Anglo-French verb trencher, meaning "to cut," and may ultimately derive from the Vulgar Latin trinicare, meaning "to cut in three." Hence, a trenchant sword is one with a keen edge; a trenchant remark is one that cuts deep; and a trenchant observation is one that cuts to the heart of the matter. Relatives of trenchant in English include the noun trench ("a long ditch cut into the ground") and the verb retrench ("to cut down or pare away" or "to cut down expenses").