Ring Frenchwoman covered in dirt (7)
I believe the answer is:
grommet
'ring' is the definition.
(protective ring used in electronics)
'frenchwoman covered in dirt' is the wordplay.
'frenchwoman' becomes 'mme' (abbreviation for madame).
'covered in' means one lot of letters goes inside another.
'dirt' becomes 'grot' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mme' going into 'grot' is 'GROMMET'.
Can you help me to learn more?
(Other definitions for grommet that I've seen before include "Tube in eardrum to drain and ventilate ear" , "Ring for hole - tube for eardrum" , "Ring of rubber to line a hole and prevent chafing" , "Eyelet's metal ring" , "Washer; eyelet" .)