Footwear parts, though only small (5)
I believe the answer is:
soles
'footwear parts' is the definition.
'soles' can be an answer for 'parts' (sol is a kind of part). I'm unsure of the 'footwear' bit.
'only small' is the wordplay.
'only' becomes 'sole' (synonyms).
'small' becomes 's' (abbreviation - e.g. clothes size).
'sole'+'s'='SOLES'
'though' acts as a link.
Can you help me to learn more?
(Other definitions for soles that I've seen before include "Undersides of feet" , "Parts of shoes" , "Shoe bottoms" , "They're always under one's feet!" , "Fish; bottoms of feet" .)