From Longman Dictionary of Contemporary EnglishIsisI‧sis /ˈaɪsɪs/ in ancient Egyptian mythology, the most important goddess. She was the goddess of nature and was also the wife and sister of Osiris.ISISNew entry // noun(Islamic State of Iraq and Syria) a violent terrorist organization that has taken control of large areas of Iraq and Syria. Its members have killed many people in a cruel way and then shown videos of the killings on the internet. ISIS is based an extreme form of Islam, which many Muslims disagree with. SYN Islamic State, IS, Da'ish
