The least stir will disturb the obsequies (4,5)
I believe the answer is:
last rites
'obsequies' is the definition.
(thesaurus)
'the least stir will disturb' is the wordplay.
'least stir' can be anagrammed to 'LAST RITES'.
Though, I am not clear how this is indicated.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for last rites that I've seen before include "Solemn ceremony" , "Those near death may be given these" , "Starlet is having final sacraments before death" , "Final ceremony" , "Final ceremonies for the dying" .)