Identical, somehow, as yours truly (4)
I believe the answer is:
same
'identical' is the definition.
(similar in meaning)
'somehow as yours truly' is the wordplay.
'somehow' indicates anagramming the letters.
'yours truly' becomes 'me' (the person that set this crossword).
'as' anagrammed gives 'sa'.
'sa'+'me'='SAME'
(Other definitions for same that I've seen before include "Identical, unchanged" , "Ditto" , "Identical or similar" , "Identical, not different" , "uniform" .)