Unable to stand still, a soldier clearly said: 'Head off! (8)

I believe the answer is:

agitated

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'unable to stand still' is the definition.
I can't tell whether this definition defines the answer.

'a soldier clearly said 'head off' is the wordplay.
'soldier clearly' becomes 'gi' (GI can mean a US soldier. I am not sure about the 'clearly' bit.).
'said' becomes 'stated' ('state' can be a synonym of 'say').
''head off' means to remove the first letter.
'stated' with its initial letter taken off is 'tated'.
'a'+'gi'+'tated'='AGITATED'

Can you help me to learn more?

(Other definitions for agitated that I've seen before include "On edge, anxious" , "Distressed" , "Shaken - upset - stirred up trouble" , "Worked up, flustered" , "Aroused - disturbed" .)

I've seen this clue in The Irish Times.

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