Clue: Warning about ringing university hospital is rot (8)
Answer: LANGUISH
Explanation: Definition: rot
 **Reversal of**(… about) SIGNAL(a warning/an indication of, perhaps, danger in a situation) **containing**(ringing) U(abbrev. for "university") + H(abbrev. for "hospital").
Defn: …/to decay, as a result of neglect.