Explosive, brief loudness may lead to intensive care (8)
I believe the answer is:
volcanic
'explosive' is the definition.
(thesaurus)
'brief loudness may lead to intensive care' is the wordplay.
'brief loudness' becomes 'vol' (I can't explain this - if you can you should give a lot more credence to this answer).
'may' becomes 'can' (synonyms).
'lead' means one lot of letters go next to another.
'to intensive care' becomes 'IC' (abbreviation for intensive care).
'vol'+'can'+'ic'='VOLCANIC'
Can you help me to learn more?
(Other definitions for volcanic that I've seen before include "Of Etna etc" , "Relating to eruption in earth's surface" , "Relating to fissures which produce lava" , "given to sudden outbursts" , "Like lava, perhaps" .)