Motorists keeping dry at home, and secure (6)
I believe the answer is:
attain
'secure' is the definition.
(I've seen this in another clue)
'motorists keeping dry at home' is the wordplay.
'motorists' becomes 'AA' (Automobile Association).
'keeping' is an insertion indicator (some letters kept inside).
'dry' becomes 'tt' (abbreviation for teetotal).
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'aa' enclosing 'tt' is 'atta'.
'atta'+'in'='ATTAIN'
'and' acts as a link.
(Other definitions for attain that I've seen before include "Succeed in accomplishing; reach" , "Achieve with effort" , "Reach (age, size etc.)" , "Succeed in doing, get there" , "Succeed in reaching, achieve" .)