Selectively tighten security under pressure (5)
I believe the answer is:
tense
'under pressure' is the definition.
(I've seen this before)
'selectively tighten security' is the wordplay.
'TENSE' is hidden in amongst the letters.
However, I am unsure how this is indicated.
Can you help me to learn more?
(Other definitions for tense that I've seen before include "Form of verb showing time" , "Nervous or tight" , "Under emotional strain" , "Strained by time in grammar" , "Uneasy" .)