State of Aunt Kath, regularly (4)
I believe the answer is:
utah
'state' is the definition.
(I know that Utah is an US state)
'aunt kath regularly' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'aunt'+'kath'='auntkath'
The alternate letters of 'auntkath' are 'UTAH'.
'of' is the link.
(Other definitions for utah that I've seen before include "Mormons are found here in a hut" , "A hut marks the State" , "American state associated with Mormons and their faith" , "Mormon US state" , "A hut for the Mormons, oddly" .)