Slightly damage second part of shirt (5)
I believe the answer is:
scuff
'slightly damage' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'second part of shirt' is the wordplay.
'second' becomes 's' (common abbreviation).
'part of shirt' becomes 'cuff' (part of a shirt sleeve).
's'+'cuff'='SCUFF'
Can you help me to learn more?
(Other definitions for scuff that I've seen before include "Scrape (shoe, etc)" , "drag, while walking" , "Scrape (eg, a shoe)" , "Scrape (shoe leather)" , "Scrape (shoes) when walking" .)