Frank’s back from trip, one spent in former East Germany (8)
I believe the answer is:
postmark
'frank's' is the definition.
(synonyms)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for postmark that I've seen before include "Stamp franking" , "It is stamped on envelope" , "Letter franking" , "It shows date and time of mailing" , "Stamp cancellation" .)