Servant turned up on date bringing rock (7)
I believe the answer is:
diamond
'rock' is the definition.
(thesaurus)
'servant turned up on date' is the wordplay.
'servant' becomes 'maid' (maid is a kind of servant**).
'turned up' is a reversal indicator.
'date' becomes 'd' (common abbreviation eg in DOB, date of birth).
'maid' in reverse letter order is 'diam'.
'diam'+'on'+'d'='DIAMOND'
'bringing' is the link.
(Other definitions for diamond that I've seen before include "Suit-baseball field - gem" , "Very hard substance" , "One of her best friends" , "Carbon gemstone" , "Gemstone - baseball field" .)