Medical specialty (10)
(Another definition for neurology that I've seen is " Study of the nervous system".)
(Other definitions for obstetrics that I've seen before include "medical speciality" , "Branch of medicine dealing with childbirth" , "Perinatal medicine" , "medical department" .)
'medical specialty' is the definition.
(abbreviation for Ear, Nose and Throat)
This is the entire clue.
(Other definitions for ent that I've seen before include "Tolkien tree-man" , "Tolkien's Treebeard, for one" .)