The girl adopted by mainly clever and dazzling type (7)
I believe the answer is:
smasher
'dazzling type' is the definition.
'the girl adopted by mainly clever' is the wordplay.
'the girl' becomes 'she' (**).
'adopted by' is an insertion indicator (I've seen this in other clues).
'mainly' means to remove the last letter.
'clever' becomes 'smart' ('smart' can be similar in meaning to 'clever').
'smart' with its last letter removed is 'smar'.
'she' placed inside 'smar' is 'SMASHER'.
'and' acts as a link.
(Other definitions for smasher that I've seen before include "Beauty" , "one breaks into pieces" , "Effective tennis player" , "Pretty woman" , "who is attractive to men?" .)