In the interim, e-mail when worried (9)
I believe the answer is:
meanwhile
'in the interim' is the definition.
(I've seen this before)
'e-mail when worried' is the wordplay.
'worried' indicates anagramming the letters.
'e'+'mail'+'when'='emailwhen'
'emailwhen' with letters rearranged gives 'MEANWHILE'.
(Other definitions for meanwhile that I've seen before include "simultaneously" , "On the other hand" , "In the intervening time" , "In the interim" , "For the moment" .)