Await former favourite, catching cold (6)
I believe the answer is:
expect
'await' is the definition.
('expect' can be a synonym of 'await')
'former favourite catching cold' is the wordplay.
'former' becomes 'ex'.
'favourite' becomes 'pet' ('pet' can be a synonym of 'favourite').
'catching' means one lot of letters goes inside another.
'cold' becomes 'c' (eg on taps).
'pet' enclosing 'c' is 'pect'.
'ex'+'pect'='EXPECT'
(Other definitions for expect that I've seen before include "demand and > have prospects" , "Think of as likely to happen" , "Hope - await" , "Believe about to happen" , "Wait for" .)