Splitting up is a common way of referring to the end of a relationship or the act of dividing something into smaller parts. When it comes to synonyms for the word "split up", there are plenty of options, such as "separate", "divorce", "part ways", "break up", "disband", "dismantle", "disperse", "scatter", "segment", "slice", "share", "divvy up" and "partition". Each of these words can be used in different contexts to convey the idea of a separation or division, whether it is personal or organizational. The choice of word used often depends on the tone and nuance desired, making it important to select the right synonym for the right situation.