Faculty US monk regularly visited in season (6)
I believe the answer is:
autumn
'season' is the definition.
(autumn is a season)
'faculty us monk regularly visited' is the wordplay.
'regularly visited' means one should take alternating letters (letters are taken at regular intervals).
'faculty'+'us'+'monk'='facultyusmonk'
The alternate letters of 'facultyusmonk' are 'AUTUMN'.
'in' acts as a link.
(Other definitions for autumn that I've seen before include "Season, has its music too (Keats)" , "Fall in North America" , "Fall for 33 across" , "Season of decay" , "1 Season of mists and mellow fruitfulness" .)