Tyro from apothecary grew up steeped in the adventures of Geronimo presumably (6)
I believe the answer is:
apache
'tyro' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for apache that I've seen before include "Fierce Indian of American SW, or Paris ruffian" , "member of tribe" , "Member of a native American people" , "Parisian ruffian - Indian" , "North American native tribe" .)