Busy hospital with heads of Intensive Care covering up shock therapy (6)
I believe the answer is:
hectic
'busy' is the definition.
(thesaurus)
'hospital with heads of intensive care covering up shock therapy' is the wordplay.
'hospital' becomes 'h' (abbreviation for hospital on maps).
'with' says to put letters next to each other.
'heads of' suggests taking the first letters.
'covering up' means one lot of letters goes inside another.
'shock therapy' becomes 'ECT' (ECT is an example).
The initial letters of 'intensive care' is 'ic'.
'h'+'ic'='hic'
'hic' enclosing 'ect' is 'HECTIC'.
(Other definitions for hectic that I've seen before include "Bustling" , "Marked by intense activity" , "'Excited, flustered or rushed (6)'" , "particularly busy" , "Involving feverish activity, chaotic" .)