Normally Laura's out with sweetheart (2,1,4)
I believe the answer is:
as a rule
'normally' is the definition.
(thesaurus)
'laura's out with sweetheart' is the wordplay.
'out with' indicates an anagram (out can mean wrong or inaccurate).
'sweetheart' becomes 'e' (the heart/centre of 'sweet').
'lauras' anagrammed with 'e' can make 'AS A RULE'.
(Other definitions for as a rule that I've seen before include "Mainly" , "none straighter" , "in the main" , "how one might take a calibrated rod" , "In most cases" .)