al-Qae·da or al-Qai·da 
(ăl-kādə, -kīdə)
(ăl-kādə, -kīdə)n.
An international organization of loosely affiliated cells that carry out attacks and bombings in the attempt to disrupt the economies and influence of Western nations and advance Islamic fundamentalism.
[Arabic al-qā'ida, the base : al-, the + qā'ida, base, feminine active participle of qa'ada, to sit; see qʿd in the Appendix of Semitic roots.]