Minatory. adjective: 1. menacing; threatening: the minatory actions of a criminal when it comes to blackmail, extortion, and thinly-veiled threats.

Quotes: “His features had lost their delicately benevolent aspect; his words were minatory.
” — E. Phillips Oppenheim, The Vanished Messenger, 1914

“The latest of the desperate devices of Mr. Oxnard is now bearing its fruit in the minatory letters that are coming to members of Congress who have beet-raisers among their constituents, warning them that they will fail of re-election if they prefer the behests of public duty to those of Oxnard.” 
– James Kaplan, “Mr. Oxnard’s Clients,” New York Times, January 18, 1902

Origin: The English adjective minatory has always stuck pretty closely to its Latin source, minārī “to threaten,” a derivative of the noun minae “threats, menaces.” Another derivative in Latin is the Late Latin noun minātor, “one who drives cattle with threats, drover.” This “country” usage persisted in French, in which the verb mener, a direct descendant of Latin minārī, means “to lead.” Minatory entered English in the 16th century.