Aqidah (, plural , ʿaqāʾid, also sometimes spelled Aqeeda, ʿAqīdah or ʿAqīda) is an Islamic term meaning creed. Many schools of Islamic theology expressing different views on aqidah exist. Any religious belief system, or creed, can be considered an example of aqidah. However, this term has taken a significant technical usage in Muslim history and theology, denoting those matters over which Muslims hold conviction. It is a branch of Islamic studies describing the beliefs of Islam.
Literally, the word ʿaqīdah is derived from the Semitic root ʿqd (ʿaqada), which means "to tie" or "knot".