assassinate

Short definition from Wiktionary

Verb

1. 1
   To murder someone, especially an important person, by a sudden or obscure attack, especially for ideological or political reasons.
2. 2
   To harm, ruin, or defame severely or destroy by treachery, slander, libel, or obscure attack.

Noun

1. 1
   Assassination, murder.
2. 2
   An assassin.