Unobtrusive (8)
I believe the answer is:
discreet
'unobtrusive' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for discreet that I've seen before include "Cautious, not giving away secrets" , "Doesn't give away secrets - can be trusted" , "Unobtrusive; careful and prudent" , "Careful not to attract attention" , "Unobtrusive, circumspect" .)