Stand outside quarters in a state of the jitters (5)
I believe the answer is:
tense
'a state of the jitters' is the definition.
I can't judge whether this definition defines the answer.
'stand outside quarters' is the wordplay.
'stand' becomes 'tee' (I've seen this before).
'outside' indicates putting letters inside.
'quarters' becomes 'ns'.
'tee' enclosing 'ns' is 'TENSE'.
'in' is the link.
Can you help me to learn more?
(Other definitions for tense that I've seen before include "contract" , "Rigid, or grammatical time" , "Stretched tightly, unable to relax" , "Unrelaxed; form of verb" , "past, say" .)