Small chip losing initial pigment (4)

I believe the answer is:

lake

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'pigment' is the definition.
(I know that lake is a type of pigment)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for lake that I've seen before include "Erie or Woebegone" , "Pool" , "Large pond; pigment" , "Inland body of water" , "E.g. Huron" .)

I've seen this clue in The Independent.

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