The phrase "done a turn" typically means to have completed a job or task. There are many synonyms for this phrase that can be used to convey the same idea in different contexts or for added variety in writing. Some common alternatives include accomplished, finished, performed, executed, fulfilled, achieved, carried out, and concluded. Each of these options provides a slightly different nuance or emphasis, such as highlighting the initiative or effort required to complete the task or noting the finality of the action. The right synonym will depend on the tone and intended meaning of the sentence or passage.