Second edition gets studied in alarm (5)
I believe the answer is:
dread
'alarm' is the definition.
(I've seen this before)
'second edition gets studied' is the wordplay.
'second edition' becomes 'd' (2nd letter of 'edition').
'gets' is a charade indicator (letters next to each other).
'studied' becomes 'read' (to read a subject is to study it at university).
'd'+'read'='DREAD'
'in' acts as a link.
(Other definitions for dread that I've seen before include "Anticipate with fear" , "fright" , "Adder (anag)" , "Terrible fear" , "Great fear or apprehension" .)