Bond, not so informally dressed? (7)

I believe the answer is:

tieless

'informally dressed?' is the definition.
(not wearing a tie)

'bond not' is the wordplay.
'bond' becomes 'tie' (both can mean a connection).
'not' becomes 'less' (I've seen this in other clues).
'tie'+'less'='TIELESS'

'so' is the link.

(Another definition for tieless that I've seen is " in an open-neck shirt?".)

I've seen this clue in The Times.

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