### Clue: River estuaries separated by grand locks (8)
### Answer: RINGLETS 
 ### Explanation: Definition: locks
 R(abbrev. for "river") + INLETS(estuaries/narrows strips of water from the sea or a lake into the land) **containing**(separated by) G(abbrev. for "grand"/a thousand dollars or pounds).
Defn:  … of hair.