Block steps to secure source of funding (6)
I believe the answer is:
stifle
'block' is the definition.
(thesaurus)
'steps to secure source of funding' is the wordplay.
'steps' becomes 'stile' (I've seen this in another clue).
'to secure' indicates putting letters inside (inserted letters are secured inside).
'source of' indicates taking the first letters.
The initial letter of 'funding' is 'f'.
'stile' enclosing 'f' is 'STIFLE'.
(Other definitions for stifle that I've seen before include "Muffle, suppress" , "Curb" , "Part of animal's leg" , "Have difficulty breathing" , "Smother, suffocate" .)