Bone tired, lacking resistance, turning docile (8)
I believe the answer is:
obedient
'docile' is the definition.
('obedient' can be similar in meaning to 'docile')
'bone tired lacking resistance turning' is the wordplay.
'lacking' suggests deleting specific letters.
'resistance' becomes 'r' (abbreviation).
'turning' indicates anagramming the letters.
'bone'+'tired'='bonetired'
'bonetired' with 'r' removed is 'bonetied'.
'bonetied' anagrammed gives 'OBEDIENT'.
(Other definitions for obedient that I've seen before include "Ready to comply" , "Complying with orders" , "Following instructions" , "Doing as one's told" , "A good dog should be" .)