What term refers specifically to the anatomical structure of the eyelid?

The term that specifically refers to the anatomical structure of the eyelid is "blephar/o." This root is derived from the Greek word "blepharon," which means eyelid. It is commonly used in medical terminology related to conditions, procedures, and anatomy involving the eyelids. For example, blepharitis refers to inflammation of the eyelid, and blepharoplasty refers to surgical repair of the eyelid.

The other terms listed are associated with different anatomical structures: "bucc/o" relates to the cheek or mouth area, "brachi/o" pertains to the arm, and "burs/o" refers to bursae, which are fluid-filled sacs that reduce friction between tissues in joints. Each of these terms denotes a specific aspect of anatomy unrelated to the eyelid, reinforcing why "blephar/o" is the correct choice for this question.