Attentive ambassador fled, running around university (7)
I believe the answer is:
heedful
'attentive' is the definition.
(heedful can mean listening or paying attention)
'ambassador fled running around university' is the wordplay.
'ambassador' becomes 'he' (His or Her Excellency).
'running' indicates an anagram (the letters run around to different places).
'around' is an insertion indicator.
'university' becomes 'U' (abbreviation as in UMass).
'fled' with letters rearranged gives 'edfl'.
'edfl' going around 'u' is 'edful'.
'he'+'edful'='HEEDFUL'
(Other definitions for heedful that I've seen before include "Attentive - circumspect" , "Attentive, listening carefully" , "Wary" , "Paying careful attention" , "Cautious" .)