c. 1200, vertu, "moral life and conduct; a particular moral excellence," from Anglo-French and Old French vertu "force, strength, vigor; moral strength; qualities, abilities" (10c. in Old French), from Latin virtutem (nominative virtus) "moral strength, high character, goodness; manliness; valor, bravery, courage (in war); excellence, worth," from vir "man" (from PIE root *wi-ro- "man").
For my part I honour with the name of virtue the habit of acting in a way troublesome to oneself and useful to others. [Stendhal "de l'Amour," 1822]
Especially (in women) "chastity, sexual purity" from 1590s. Phrase by virtue of (early 13c.) preserves alternative Middle English sense of "efficacy." Wyclif Bible has virtue where KJV uses power. The seven cardinal virtues (early 14c.) were divided into the natural (justice, prudence, temperance, fortitude) and the theological (hope, faith, charity). To make a virtue of a necessity (late 14c.) translates Latin facere de necessitate virtutem [Jerome].
"seduced or corrupted from duty or virtue, vitiated in morals or purity of character," 1590s, past-participle adjective from debauch (v.). Related: Debauchedness.
c. 1200, ypocrite, "false pretender to virtue or religion," from Old French ypocrite (12c., Modern French hypocrite), from Church Latin hypocrita "a hypocrite," from Greek hypokritēs "stage actor; pretender, dissembler," from hypokrinesthai (see hypocrisy).
1795, in specific sense of "government intimidation during the Reign of Terror in France" (March 1793-July 1794), from French terrorisme, noted in English by 1795 as a coinage of the Revolution, from Latin terror "great fear, dread, alarm, panic; object of fear, cause of alarm; terrible news," from PIE root *tres- "to tremble" (see terrible).
If the basis of a popular government in peacetime is virtue, its basis in a time of revolution is virtue and terror — virtue, without which terror would be barbaric; and terror, without which virtue would be impotent. [Robespierre, speech in French National Convention, 1794]
General sense of "systematic use of terror as a policy" is first recorded in English 1798 (in reference to the Irish Rebellion of that year). At one time, a word for a certain kind of mass-destruction terrorism was dynamitism (1883); and during World War I frightfulness (translating German Schrecklichkeit) was used in Britain for "deliberate policy of terrorizing enemy non-combatants."