Tart and redhead embraced by tart (5)
I believe the answer is:
acrid
'tart' is the definition.
(I've seen this before)
'redhead embraced by tart' is the wordplay.
'redhead' becomes 'r' (the head/first letter of 'red').
'embraced by' indicates putting letters inside.
'tart' becomes 'acid' (I've seen this before).
'r' inserted inside 'acid' is 'ACRID'.
'and' is the link.
(Other definitions for acrid that I've seen before include "Greek goddess" , "Having a bitter taste or small, like smoke" , "irritating" , "Bitter - caustic" , "Tart" .)