Defence sent off for damages (5)

I believe the answer is:
dents
'damages' is the definition.
(dent is a kind of damage)
'defence sent off' is the wordplay.
'defence' becomes 'd' (this might be a standard abbreviation of which I'm unaware).
'off' is an anagram indicator.
'sent' anagrammed gives 'ents'.
'd'+'ents'='DENTS'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for dents that I've seen before include "Tends towards small depressions" , "Tends towards small depression" , "Tends to create small depressions" , "reductions in size" .)
