Avoiding commitment (7)
(Other definitions for guarded that I've seen before include "Reticent" , "with escort" , "Cautious, having reservations" , "Cautious; watched over" , "Protected from a drudge" .)
'avoiding commitment' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for evasive that I've seen before include "Avoiding giving answers" , "Not frank, shifty" , "make out-of-the-way sort of action" , "Shifty, hard to pin down" , "Avoiding answering" .)