Final answer:
The term for idle chatter that compares extensive conversation with little outcome to chewing with little sustenance is 'Chew the fat.' It is the answer to the schoolwork question, with other options being less relevant to the analogy provided in the question.
Step-by-step explanation:
The term for idle chatter that refers to getting little substance out of a lot of talking is 'C) Chew the fat.' This phrase originated as a metaphor for conversing in a leisurely manner, similar to the way one might slowly chew on fat without getting much nutrition. It compares the act of talking extensively with little concrete outcome to the effort of masticating with little sustenance.
Neither 'A) Gobbledegook,' which refers to nonsensical or complicated language, 'B) Small talk,' which is casual conversation about unimportant matters, nor 'D) Chatterbox,' which describes a person who talks excessively, match the meaning implied by the question. Therefore, the correct answer is 'C) Chew the fat,' directly relating to idle chatter with an analogy to mastication and sustenance.