Submissive, docile (4)
I believe the answer is:
tame
I believe this is a double definition.
'submissive' is the first definition.
(I've seen this in another clue)
'docile' is the second definition.
(similar in meaning)
(Other definitions for tame that I've seen before include "Not wild, unexciting" , "Not exciting; cooperative" , "Not exciting; domesticate" , "Restrained" , "Domesticated, not wild" .)