River with drop showing signs of use (4,3,4)
I believe the answer is:
wear and tear
'signs of use' is the definition.
(wear and tear is damage caused by regular use)
'river with drop' is the wordplay.
'river' becomes 'wear' (river in the north east of England).
'with' becomes 'and'.
'drop' becomes 'tear' (teardrop).
'wear'+'and'+'tear'='WEAR AND TEAR'
'showing' is the link.
(Other definitions for wear and tear that I've seen before include "Result of using" , "Damage from ordinary use" , "Gradual damage" , "Two examples of running water" , "uninsurable damage" .)