WordNet sense 1 (a clandestine group of southeast Asian terrorists organized in 1993 and trained by al-Qaeda; supports militant Muslims in Indonesia and the Philippines and has cells in Singapore and Malaysia and Indonesia):

JI, Jemaah Islamiyah, Islamic Community, Malaysia Militant Group, Malaysian Mujahidin Group

WordNet sense 2 (a terrorist organization of militant Islamists organized into tiny cells of extreme fundamentalists; emerged during the 1970s mainly in Egyptian jails):

al-Gama'a al-Islamiyya