Baselessly refers to something that lacks a basis or foundation. There are several synonyms for this term that can be used interchangeably in various situations. Some of the synonyms include groundlessly, unfoundedly, unjustifiably, without justification, without proof, falsely, wrongly, and speciously. Each of these synonyms accurately describes the concept of baselessly, and a writer or speaker can choose the most appropriate word depending on the context. Using a synonym for baselessly can help to add variety to the language and make the message more persuasive and engaging.