One having turned up barman at first tolerated? (3,4)

'one' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'turned up barman at first tolerated?' is the wordplay.
'turned' says the letters should be written backwards.
'at first' suggests taking the first letters.
'tolerated?' becomes 'bore' (I've seen this in another clue).
The initial letter of 'barman' is 'b'.
'up' written backwards gives 'pu'.
'pu'+'b'+'bore'='PUB BORE'

'having' acts as a link.