Comprehensive school's head in tears (8)
I believe the answer is:
sweeping
'comprehensive' is the definition.
(I've seen this before)
'school's head in tears' is the wordplay.
'head' says to take the initial letters.
'in tears' becomes 'weeping' (I've seen this before).
The first letter of 'schools' is 's'.
's'+'weeping'='SWEEPING'
(Other definitions for sweeping that I've seen before include "Wide-ranging and comprehensive - also cleaning?" , "Using a broom" , "clearing the mess?" , "tidying up" , "Too general; cleaning" .)