Name Lennox, Hall and Oakley as childminders (7)
I believe the answer is:
nannies
'childminders' is the definition.
(a nanny looks after children)
'name lennox hall and oakley' is the wordplay.
'name' becomes 'n' (common abbreviation e.g. on forms).
'lennox hall and oakley' becomes 'Annies' (Annie Lennox, Annie Hall and Annie Oakley).
'n'+'annies'='NANNIES'
'as' acts as a link.
(Other definitions for nannies that I've seen before include "female servants?" , "Children's nurses" , "Childminders" , "They look after children" , "Child minders" .)