Pick up dress to show off (4)
I believe the answer is:
brag
'show off' is the definition.
(both can mean to boast about something)
'pick up dress' is the wordplay.
'pick up' is a reversal indicator.
'dress' becomes 'garb' (synonyms).
'garb' back-to-front is 'BRAG'.
'to' is the link.
(Other definitions for brag that I've seen before include "Blow one's own trumpet" , "Boast, exaggerate" , "Show off, crow" , "boast; form of poker" , "Boast, crow" .)