Novelty: something new or unusual (https://www.merriam-webster.com/dictionary/novelty​)
We define a research gap as a topic or area for which missing or inadequate information limits the ability of reviewers to reach a conclusion for a given question. A research gap may be further developed, such as through stakeholder engagement in prioritization, into research needs. (https://www.ncbi.nlm.nih.gov/books/NBK126702/)