Second biggest one in range, harder than the others (8)
I believe the answer is:
severest
'harder than the others' is the definition.
(the most hard or severe)
'second biggest one in range' is the wordplay.
'second' becomes 's' (common abbreviation).
'biggest one in range' becomes 'Everest' (largest mountain of the Himalayas).
's'+'everest'='SEVEREST'
(Other definitions for severest that I've seen before include "Most dangerous" , "Most extreme or difficult" , "Most harsh and punitive" , "Most strict and harsh" .)