Dead cross, being held by French and in court (7)
I believe the answer is:
extinct
'dead' is the definition.
('extinct' can be similar in meaning to 'dead')
'cross being held by french and in court' is the wordplay.
'cross' becomes 'x'.
'being held by' indicates putting letters inside.
'french and' becomes 'et' ('and' in the French language).
'court' becomes 'ct'.
'x' placed within 'et' is 'ext'.
'ext'+'in'+'ct'='EXTINCT'
(Other definitions for extinct that I've seen before include "Dead (as a dodo?)" , "Put out" , "gone for ever" , "Of volcano, no longer active" , "Ended" .)