Female bird initially installed in strange element (7)
I believe the answer is:
rhenium
'element' is the definition.
(rhenium is a kind of element)
'female bird initially installed in strange' is the wordplay.
'female bird' becomes 'hen' (I've seen this before).
'initially' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'strange' becomes 'rum' (similar in meaning).
The initial letter of 'installed' is 'i'.
'hen'+'i'='heni'
'heni' inserted into 'rum' is 'RHENIUM'.
(Other definitions for rhenium that I've seen before include "Element (Re)" , "Metal" , "Chemical" .)