Woman's conserving fifty historical records (6)
I believe the answer is:
annals
'historical records' is the definition.
(I've seen this in another clue)
'woman's conserving fifty' is the wordplay.
I cannot quite see how this works, but
'fifty' could be 'l' (Roman numeral) and 'l' is found within the answer.
'woman's' could be 'annas' and 'annas' is located in the leftover letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for annals that I've seen before include "Chronicles" , "Chronological records, yearbooks" , "Yearly records" , "Record of events year by year" , "Tomorrow (Spanish)" .)