Instilled deeply in English: bad weather and, regularly, feuds (9)
I believe the answer is:
engrained
'instilled deeply' is the definition.
'english bad weather and regularly feuds' is the wordplay.
'english' becomes 'eng'.
'bad weather' becomes 'rain' (rain is an example of bad weather).
'and' says to put letters next to each other.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
The alternating letters of 'feuds' are 'ed'.
'eng'+'rain'+'ed'='ENGRAINED'
'in' is the link.
(Another definition for engrained that I've seen is " immovable".)