Pack animal left priest in the high mountains (5)
I believe the answer is:
llama
'pack animal' is the definition.
(llamas are often used as pack animals)
'left priest in the high mountains' is the wordplay.
I cannot really understand how this works, but
'left' could be 'l' (common abbreviation) and 'l' is found in the answer.
'priest' could be 'lama' (lama is a kind of priest) and 'lama' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for llama that I've seen before include "Andean beast of burden" , "Animal related to camels but smaller and lacking a hump" , "Domesticated South American beast" , "South American cud-chewing mammal" , "Andean 'camel'" .)