A lot of hair to clean up (3)
I believe the answer is:
mop
'clean up' is the definition.
(I've seen this in another clue)
'a lot of hair' is the wordplay.
'a lot' becomes 'm'.
'of hair' becomes 'op' (I can't justify this - if you can you should give a lot more credence to this answer).
'm'+'op'='MOP'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for mop that I've seen before include "Bundle of soft material at end of stick for cleaning" , "Swab" , "Hair, unkempt" , "Shock of hair; soak (up)" , "Implement for washing floor" .)