The girl’s been stood up again and that’s tough (6)
I believe the answer is:
severe
'that's tough' is the definition.
(thesaurus)
'the girl's been stood up again' is the wordplay.
'the girl's' becomes 'eves' (**).
'been stood up' is a reversal indicator (I've seen 'being stood up' mean this (in a down clue, letters go up)).
'again' becomes 're'.
'eves' written backwards gives 'seve'.
'seve'+'re'='SEVERE'
'and' acts as a link.
(Other definitions for severe that I've seen before include "Harsh and punitive" , "Harsh and stern" , "Austere, serious" , "'Strict, harsh (6)'" , "Harsh; very plain" .)