Language lawyers use when winds burst into shelter! (8)
I believe the answer is:
legalese
'language lawyers use' is the definition.
(legal language)
'winds burst into shelter' is the wordplay.
'winds' becomes 'gales' (gale is a kind of wind).
'burst into' is an insertion indicator.
'shelter' becomes 'lee' (as in lee side, the side sheltered from wind).
'gales' going within 'lee' is 'LEGALESE'.
'when' acts as a link.
(Other definitions for legalese that I've seen before include "contract wording?" , "such language at the bar!" , "barman's peculiar words" , "Solicitor's jargon" , "formal language" .)