Scold harshly or punish severely; also, put a stop to something. For example, If you're caught smoking in school, the principal is bound to lower the boom on you, or The new radar equipment enabled the police to lower the boom on speeding. This expression refers to the boom of a sailboat—a long spar that extends from the mast to hold the foot of the sail. In a changing wind, the boom can swing wildly, leaving one at risk of being struck. [Slang; first half of 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.