Answer: Suffix
When defining a medical term, one begin the definition with the definition of SUFFIX.
Step-by-step explanation:
Suffix refers to words added to the end of words to add meaning to the words or change the word functions.
When defining a medical term, one begin the definition with the definition of SUFFIX or you define at the end because the suffix of medical terms signifies procedures, diseases, conditions which is added to prefix( word that begin) which signify the meaning of term and give anatomical location or function.