Old lady's detailed minding a cosmetic (7)

I believe the answer is:

mascara

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'cosmetic' is the definition.
(I know that mascara is a type of make-up)

'old lady's detailed minding a' is the wordplay.
'old lady's' becomes 'ma's' (both can informally mean mother).
'detailed' means to remove the last letter (the word must be end-less or 'de-tailed').
'minding' becomes 'scar' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mas' with its final letter taken away is 'ma'.
'ma'+'scar'+'a'='MASCARA'

Can you help me to learn more?

(Other definitions for mascara that I've seen before include "for application of lashes" , "that accentuates lashes" , "Make-up item" , "Eyelash cosmetic" , "Type of make-up" .)

I've seen this clue in The Telegraph.

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