Slyly shy (3)
I believe the answer is:
coy
'slyly shy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for coy that I've seen before include "Affectedly modest or shy" , "Military team in brief" , "Reserved" , "Pretending to be shy or bashful" , "Group of soldiers" .)