Clear throat after foul smell starts to infiltrate awful old country (7)

I believe the answer is:

bohemia

I'm a little stuck... Click here to teach me more about this clue!

'old country' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for bohemia that I've seen before include "Czech region" , "Part of the Czech Republic" , "quarter of artists" , "old kingdom" , "Former Slavic kingdom" .)

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app