Derisive star having no time to meet academic in charge (8)
I believe the answer is:
sardonic
'derisive' is the definition.
(thesaurus)
'star having no time to meet academic in charge' is the wordplay.
'having no' suggests deleting specific letters.
'time' becomes 't'.
'to meet' is a charade indicator (letters next to each other).
'academic' becomes 'don' (I've seen this before**).
'in charge' becomes 'ic'.
'star' with 't' taken out is 'sar'.
'sar'+'don'+'ic'='SARDONIC'
(Other definitions for sardonic that I've seen before include "Grimly cynical" , "Derisively ironic" , "Cynical -- so rancid (anag)" , "Disdainfully or ironically humorous" , "Tart" .)