Son left in club to speak explosively (8)
I believe the answer is:
splutter
'speak explosively' is the definition.
'son left in club' is the wordplay.
'son' becomes 's'.
'left' becomes 'l' (common abbreviation).
'in' is an insertion indicator.
'club' becomes 'putter' (putter is a kind of club).
'l' put inside 'putter' is 'plutter'.
's'+'plutter'='SPLUTTER'
'to' acts as a link.
(Other definitions for splutter that I've seen before include "Speak with a spitting sound" , "Make spitting sounds when speaking (in a rage?)" , "Speak rapidly and indistinctly, as in anger" , "Throw out droplets or sparks" , "Scatter liquid" .)