U ‧ na ‧ bomb ‧ er /ˈjuːnəˌbɒməʳ $ -ˌbɑː-/ BrE AmE
the name given in newspapers etc to a man who, over a period of 18 years, sent 16 bombs through the mail to US universities and other organizations, in order to protest against ↑ technology . In 1996 the FBI arrested Theodore Kaczynski, a former university ↑ professor , for these crimes, and in 1998 he was sent to prison for life.