A fitting suggestion (3,2,2)
I believe the answer is:
try it on
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for try it on that I've seen before include "Attempt to deceive" , "practise a little deception" , "be bold" , "Deliberately test someone's patience (colloq.)" , "check garment before purchase" .)