School head was concerned and frightened (6)
I believe the answer is:
scared
'frightened' is the definition.
(scared means frightened or fearful)
'school head was concerned' is the wordplay.
'head' says to take the initial letters.
'was concerned' becomes 'cared' (had a care).
The initial letter of 'school' is 's'.
's'+'cared'='SCARED'
'and' acts as a link.
(Other definitions for scared that I've seen before include "Frightened or intimidated" , "having kittens" , "Afraid, anxious" , "Frightened or apprehensive" , "Fearful, anxious" .)