Burst into tears, nasty head being very loud (10)
I believe the answer is:
stentorian
'very loud' is the definition.
(I've seen this before)
'burst into tears nasty head' is the wordplay.
'burst' indicates an anagram.
'head' indicates taking the first letters.
The first letter of 'nasty' is 'n'.
'into'+'tears'='intotears'
'intotears' with letters rearranged gives 'stentoria'.
'stentoria'+'n'='STENTORIAN'
'being' is the link.
(Other definitions for stentorian that I've seen before include "(Of a person's voice) loud and powerful" , "booming" , "Strident" .)