trenchant [ˈtrɛntʃənt] a.
1.) Forceful, effective, and vigorous: a trenchant argument.
2.) Caustic; cutting: trenchant criticism.
3.) Distinct; clear-cut (American Heritage Dictionary of the English Language).
Etymology: Middle English, from Old French, cutting, from present participle of trenchier, to cut.
"'So won't you young men shed this empty whinnying and prancing over victory? You should cower in abject humility in the face of the future, ever watchful for the end, whatever it may be, that the gods will cause to strike each and every one of you in retribution for your current success.' It is said that Aemilius went on in this vein for some time before dismissing the young men, with their vain and insolent pride well and truly curbed by the bridle of his trenchant words" (Roman Lives by Plutarch, Robin Wood (trans.), 1999).