Broadside from craft protecting island (6)
I believe the answer is:
tirade
'broadside' is the definition.
(I know that broadside can be written as tirade)
'craft protecting island' is the wordplay.
I cannot quite see how this works, but
'island' could be 'i' (geographical abbreviation) and 'i' is found in the answer.
'craft' could be 'trade' (synonyms) and 'trade' is found within the leftover letters.
This accounts for all the letters.
This explanation may well be incorrect...
'from' acts as a link.
Can you help me to learn more?
(Other definitions for tirade that I've seen before include "Erode or melt (material)" , "Long, abusive speech" , "Long angry piece of denunciation" , "Speech of violent denunciation" , "Prolonged speech of abuse" .)