Hit with small items of underwear (5)
I believe the answer is:
socks
'items of underwear' is the definition.
'socks' can be an answer for 'items' (I have seen 'Items of hosiery ' mean 'socks' so perhaps 'items' could also mean 'socks'). I am not sure about the 'of underwear' bit.
'hit with small' is the wordplay.
'hit' becomes 'sock' (socking is a kind of hitting).
'with' is a charade indicator (letters next to each other).
'small' becomes 's' (abbreviation - e.g. clothes size).
'sock'+'s'='SOCKS'
Can you help me to learn more?
(Other definitions for socks that I've seen before include "Hits - footwear" , "Foot covers" , "Woollen footwear or slang punches" , "Footwear - strikes" , "Hose" .)