Definition of letter bomb in US English:
 letter bomb
nounˈledər ˌbämˈlɛdər ˌbɑm
An explosive device hidden in a small package and sent to someone with the intention of harming or killing them.
as modifier letter bomb attacks
 Example sentencesExamples
-  After a woman is killed by a letter bomb, Goren and Eames find someone is going through great lengths to discredit an organization called the Foundation.
 -  He also alleged that letter bombs had been sent to his home over the years by ‘sinister forces’.
 -  A letter bomb would be quite heavy, with a thickness of more than 3 cm and dimensions of at least 10 by 15 cm.
 -  A third letter bomb was discovered before it blew up.
 -  This article describes an anarchist letter bomb of 1919.
 -  Over a period of five to seven years, particular tactics, such as arson attacks and letter bombs, come to the fore, run their course, then fade away.
 -  The identity of the American Unabomber was assisted by the analysis of saliva left on a letter bomb he sent that did not explode.
 -  On the letter bomb front, army bomb disposal experts were called on to disarm a letter bomb sent to an unnamed agricultural business and a farm.
 -  In the 1998 mail bomb explosion at the Canberra Mail Centre two postal workers were seriously injured when a letter bomb exploded during the normal sorting of mail.
 -  Four weeks ago, a letter bomb addressed to Mr Attwood was sent to the Belfast headquarters of the Policing Board.
 -  More than 100 officers worked on the hunt for McAuliffe, who was arrested three weeks after the first letter bomb was delivered early in September.
 -  Striking firemen have been warned to watch out for letter bombs after three Yorkshire men received devices through the post.
 -  The CIA had trained their field agents to recognize letter bombs and other forms of covert technology, but nothing from Jack's training raised red flags about this envelope.
 -  They were also warned to beware of letter bombs and ‘shooting attacks’.