The word "unsystematised" describes something that lacks a coherent or organised structure. Some synonyms for this term include haphazard, disorganised, chaotic, random, untidy, sporadic, and incoherent. These words convey a sense of disorderliness or lack of structure, and can be used to describe a wide range of situations. For example, someone might describe their cluttered desk as unsystematised, or a poorly-planned project as haphazard. Whether used in a professional context or everyday conversation, these synonyms can help convey the idea that something is lacking the structure or organisation needed to be effective.