Chuck's retiring (3)

I believe the answer is:

shy

This clue is a double definition.

'chuck's' is the first definition.
(both can mean to throw)

'retiring' is the second definition.
(both can mean reserved or introverted)

(Other definitions for shy that I've seen before include "Coy" , "Demure" , "'Timid, diffident (3)'" , "Bashful or timid" , "Recoil" .)

I've seen this clue in the Evening Standard.

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