There are many ways to express the concept of "non completion" with the help of synonyms. Some possible alternatives include "incomplete," "unfinished," "unfulfilled," "abandoned," "halted," "balked," "stalled," "suspended," "postponed," "delayed," "deferred," and "unrealized." Each of these words captures a slightly different aspect of the idea of something that has not been fully carried out or accomplished. Depending on the context, different synonyms may be more appropriate or effective than others, but all of them can be useful tools for writers, speakers, and communicators who want to express the nuances of this complex concept.