Less friction in knickers? (9)
I believe the answer is:
underwear
'knickers?' is the definition.
(I've seen this before)
'less friction' is the wordplay.
'less' becomes 'under' (I've seen this in other clues).
'friction' becomes 'wear' (I can't explain this - if you can you should believe this answer much more).
'under'+'wear'='UNDERWEAR'
'in' is the link.
Can you help me to learn more?
(Other definitions for underwear that I've seen before include "Combinations, say" , "bra, perhaps?" , "Endure war about smalls" , "Bloomers" , "what lies beneath that uniform!" .)