Blimey! Arsenal regularly making bloomer (6)
I believe the answer is:
correa
'bloomer' is the definition.
I know nothing about this answer so I can't judge whether this works.
'blimey arsenal regularly' is the wordplay.
'blimey' becomes 'cor' (British expression of surprise 'cor blimey!').
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternating letters of 'arsenal' are 'rea'.
'cor'+'rea'='CORREA'
'making' acts as a link.
Can you help me to learn more?
(Another definition for correa that I've seen is " Aussie shrub".)