The phrase "doth thing" refers to the act of accomplishing or performing a task. There are several synonyms that can be used in its place, including "execute," "carry out," "fulfill," "conduct," "engage in," "undertake," "perpetrate," and "accomplish." These words can be used depending on the specific context and tone desired. For example, "execute" and "conduct" may be more formal, while "engage in" and "perpetrate" may be more casual or even have negative connotations. Regardless of the synonym chosen, it is important to use clear and concise language to effectively communicate the action being taken.