Tender touch worries head of security (6)
I believe the answer is:
caress
'tender touch' is the definition.
(I've seen this in another clue)
'worries head of security' is the wordplay.
'worries' becomes 'cares' (I've seen this in another clue).
'head of' suggests taking the first letters.
The initial letter of 'security' is 's'.
'cares'+'s'='CARESS'
(Other definitions for caress that I've seen before include "Scares with loving gesture" , "Scares into handle lovingly" , "Gentle loving touch" , "Expression of affection" , "Stoke affectionately" .)