Always the first to set out for the mountain (7)
I believe the answer is:
everest
'mountain' is the definition.
(Mount Everest)
'always the first to set out for the' is the wordplay.
'always' becomes 'ever' (synonyms).
'the first' is a charade indicator (letters next to each other).
'to set out for' becomes 'es' (I am not sure about this - if you are sure you should believe this answer much more).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'ever'+'es'+'t'='EVEREST'
Can you help me to learn more?
(Other definitions for everest that I've seen before include "Himalyan peak" , "Tee revs up the mountain" , "Where Hillary was" , "One conquered in 1953" , "Mountain named after a British surveyor general of India" .)