What is "devadatta"

Devadatta ( Sanskrit and Pali: देवदत्त devadatta; Sinhalese: දේවදත්ත; ; Thewathat; Lao: ເທວະທັດ; Chinese: 提婆達多; Japanese: 提婆達多 Daibadatta; Vietnamese: Đề-Bà-Đạt-Đa) was by tradition a Buddhist monk, cousin and brother-in-law of Gautama Siddhārtha, the Sākyamuni Buddha, and brother of Ānanda, a principal student of the Buddha. Devadatta was a Shakyan and koliyan and is said to have parted from the Buddha's following with 500 other monks to form their own Sangha, most of whom are said to have been Shakya clan relatives of both Devadatta and Siddhartha.