Woman originally involved with Descartes? (5)
I believe the answer is:
irene
'woman' is the definition.
(I've seen this before)
'originally involved with descartes?' is the wordplay.
'originally' indicates taking the first letters.
'with' is a charade indicator (letters next to each other).
'descartes?' becomes 'Rene' (as in Rene Descartes the French philosopher).
The first letter of 'involved' is 'i'.
'i'+'rene'='IRENE'
(Other definitions for irene that I've seen before include "Representative of peace" , "In Greek mythology, the goddess of peace" , "Greek godess of peace" , "Goddess of peace - Byzantine ruler" , "Girl's name; Soames Forsyte's first wife" .)