A brief attempt is an endeavor that is short-lived or hastily executed. When looking for synonyms for this phrase, one might begin with alternatives to "brief" such as "short," "concise," or "succinct." Other words that could be used include "fleeting," "cursory," or "transient." Meanwhile, "attempt" can be replaced with words such as "endeavor," "venture," or "trial." Other useful synonyms include "effort," "undertaking," or "experiment." Depending on the context, it may be appropriate to use some of these words or others that more accurately describe the type of brief attempt being referenced.