"Do a job" is a phrase that is commonly used to mean completing a task or completing work. However, there are several synonyms that can be used in its place. Some of these synonyms include "perform," "execute," "undertake," "accomplish," "fulfill," and "carry out." These words are all used to convey the same message as "do a job" but may be more appropriate in certain situations. For example, "perform" may be more fitting when discussing a task that requires a certain level of skill or expertise. "Execute" could be used when describing completing a project or assignment meticulously. Each of these synonyms can help to refresh and add variety to your language.