An eleven dismissed, not half worried (7)

I believe the answer is:

anxious

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'half worried' is the definition.
'anxious' can be an answer for 'worried' (I've seen this before). I am not certain of the 'half' bit.

'an eleven dismissed not' is the wordplay.
'eleven' becomes 'xi' (Roman numerals).
'dismissed not' becomes 'ous' (I am not sure about this - if you are sure you should believe this answer much more).
'an'+'xi'+'ous'='ANXIOUS'

Can you help me to learn more?

(Other definitions for anxious that I've seen before include "On edge" , "Fretful, worried" , "Worried, nervous" , "Uneasy, worried" , "Restless" .)

I've seen this clue in The Guardian.

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