Chaucer shows that the Oxford Cleric is a starving student through his worn-off clothing and emaciated, thin horse. The character is passionate about his studies and prefers to spend money on books rather than food and clothes.
Detailed answer:
The Oxford Cleric is one of the pilgrims that do not have a very detailed description in the prologue. However, even these few details are telling. First things first, Chaucer pays attention to his physical description. We see that his coat is worn-off and almost falling apart. The character himself looks hollow and sinewy, and even his horse is skin and bones. It is safe to assume that the Cleric does not have much money and cannot cover even basic needs like food or clothes.
A “cleric” refers to a religious status best known in modern-day as clergy. It is a religious leader of some kind, a middle-class occupation in Christianity and Islam. However, from the prologue, we learn that a character is hardly a religious person. Moreover, his job does not have anything to do with religion.
Throughout his part in The Canterbury Tales, Chaucer shows the Cleric as someone who is passionate about his studies. Even though he does not talk much, his speech shows him as an educated person. It is lively, vivid, and offers quite a few interesting ideas. The Cleric tells a tale of the married couple, Walter and Griselda. Walter tests Griselda’s loyalty by taking away her children and threatening to marry another woman. It is the Cleric’s philosophic background that allows him to add an extra layer to the story. It is a metaphor for God sending sorrows to humanity and testing obedience.
Since the Oxford Cleric is drawn to philosophy. So, he prefers to spend money on books from Aristotle and other great thinkers. No wonder, he cannot buy new clothes and feed his poor horse. Like other students in Medieval England, he probably studies away from home and unsupervised. There is no wonder that he barely makes ends meet.