The term "in-efficiently" implies a lack of effectiveness or proficiency in completing a task. Some synonyms for in-efficiency include ineffective, inefficiently, unproductive, wasteful, and inept. The word "ineffective" suggests that the result achieved is not the desired one, while "inefficiently" implies that the methods used to achieve the goal were not optimal. "Unproductive" suggests that little or no work was done, while "wasteful" implies that resources were not used efficiently. "Inept" implies a lack of skill or knowledge in completing a task. In all, these synonyms convey a sense of not utilizing one's abilities and resources to the fullest extent.