Son involved in sadly real pay freeze (8)
I believe the answer is:
paralyse
'freeze' is the definition.
(freeze can mean to paralyse or stop from moving)
'son involved in sadly real pay' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'involved in' is an insertion indicator.
'sadly' indicates anagramming the letters.
'real'+'pay'='realpay'
'realpay' with letters rearranged gives 'paralye'.
's' going into 'paralye' is 'PARALYSE'.
(Other definitions for paralyse that I've seen before include "Cause to be immobile" , "Make powerless, immobile, unable to function" , "Stop everything" , "Cripple, incapacitate" , "Bring to a standstill" .)