When it comes to describing actions or situations that occur without a specific reason or cause, there are a variety of synonyms that can be used instead of "without occasion." Some examples include "unprovoked," meaning that something was done or happened spontaneously or unexpectedly, "unwarranted," which implies that there was no justifiable reason for an action or situation, and "ill-founded," which suggests that something was based on faulty or incorrect information. Other options include "groundless," "motivation-less," "uncalled for," and "purposeless." By using these alternative phrases, writers can vary their language and achieve a more nuanced or precise tone in their writing.