1. 1  a prefix meaning ânot,â freely used as an English formative, giving negative or opposite force in adjectives and their derivative adverbs and nouns (unfair; unfairly; unfairness; unfelt; unseen; unfitting; unformed; unheard-of; un-get-at-able), and less freely used in certain other nouns (unrest; unemployment). 1  Compare un-2 .
On August 7, 1998, at approximately 10:30 a.m. local time, two Embassies of the United States of America, located in the East African cities of Nairobi, Kenya and Dar es Salaam, Tanzania, were attacked in coordinated truck bombings, later determined to have occurred approximately four minutes apart.
Terror in Nairobi: the full story behind al-Shabaab's mall attack. At midday on 21 September, al-Shabaab militants stormed Nairobi's premiere shopping centre, throwing grenades and firing indiscriminately at shoppers. The subsequent siege lasted 80 hours and resulted in at least 67 deaths.