Composer Zuckerberg's baby born in South Africa (7)
I believe the answer is:
smetana
'composer' is the definition.
(I know that Smetana is a composer)
'zuckerberg's baby born in south africa' is the wordplay.
'zuckerberg's baby' becomes 'meta' (Mark Zuckerberg is the chairman of Meta).
'born' becomes 'n' (abbreviation, from the French 'nee').
'in' is an insertion indicator.
'south africa' becomes 'SA' (abbreviation).
'meta'+'n'='metan'
'metan' going into 'sa' is 'SMETANA'.
(Other definitions for smetana that I've seen before include "maker of notes" , "Czech composer, d. 1884 - Eastman (anag)" , "Bedrich ____, composer of "The Bartered Bride" and "The Kiss"" , "Nineteenth century Czech composer (The Bartered Bride)" , "Composer of The Bartered Bride; eats man (anag.)" .)