Coyest nurses agreed (3)
I believe the answer is:
yes
'agreed' is the definition.
('agreed' can mean 'yes')
'coyest nurses' is the wordplay.
'nurses' indicates the answer is hidden within the clue (nurse can mean holding closely).
'YES' can be found hidden inside 'coyest'.
(Other definitions for yes that I've seen before include "Of course" , "Yea" , "Affirmative answer" , "Aye" , "Agreed" .)