Split
Division
noun, verbal noun
Things get divided and split. We can just call this a split or division.
分裂 primarily refers to cells dividing in biology, but it can also figuratively describe an entity or group splitting into separate parts, often due to internal conflict.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その政党は三派に分裂したと思っていたんだけど、実際は四派に分裂していたんだね。
I thought the political party was split three ways, but it was actually split four ways.