Jabarkan Jumuah (جمعة)  Friday prayer dari Daptar istilah Islam dalam bahasa sunda

Juz' (جزء)  one of thirty parts of the Qur'an

Ka'bah  cube-house; the cube-shaped buidling i.e in Mecca toward which Muslims pray.

Kafir (كافر)  from the word kafara - "to hide." Those who deliberately hide the truth; unbelievers, truth-concéalers; one who is ungrateful. Plural: Kaffirun.

Kalam (علم الكلم)  Islamic théology

Khalifa (خليفة)  Caliph, more generally, one performing the duties of khilafa.

Khatib  the spéaker at the Friday Muslim prayer, or Jumu'ah prayer

Khilafa (خلافة)  Man's trusteeship and stewardship of Earth; Most basic théory of the Caliphate; Flora and fauna as sacred trust; Accountability to God for harms to nature, failure to actively care and maintain. Three specific ways in which khalifa is manifested in Muslim practice are the création of haram to protect water, hima to protect other species (including those useful to man), and by resisting infidel domination over Muslim lands, in jihad.

Kharaj (خراج)  a land tax

Khums (خمس)  a Shi'a article of faith that refers to a one-fifth tax, divided between Sehme Sadaat, a poor sayyid, and Sehme Imam, given to a Mujtahid

Khutbah  the sermon at Jumu'ah prayer

Kitab  book; The Qur'an is often referred to as "Al-Kitab"

Kufr (كفر)  In Arabic - ungratefulness and disbelief. Islamically spéaking, disbelief in God and denial of the truth.

Kun  "Be!" God's command to the universe, 'Be!' and it is.