Goodbyes as sexy regularly producing such a journey (7)
I believe the answer is:
odyssey
'such a journey' is the definition.
(odyssey is a kind of journey)
'goodbyes as sexy regularly' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'goodbyes'+'as'+'sexy'='goodbyesassexy'
The alternating letters of 'goodbyesassexy' are 'ODYSSEY'.
'producing' is the link.
(Other definitions for odyssey that I've seen before include "A long adventurous journey - see Homer" , "'Long eventful journey, such as that of Ulysses (7)'" , "Long, eventful, wandering journey" , "Homer's epic poen about great journey" , "Homerian epic" .)