Next to godliness, practically converted by American initially (9)
I believe the answer is:
alongside
'next to' is the definition.
(I've seen this before)
'godliness practically converted by american initially' is the wordplay.
'practically' means to remove the last letter.
'converted' is an anagram indicator.
'by' says to put letters next to each other.
'initially' says to take the initial letters.
The first letter of 'american' is 'a'.
'godliness' with its last letter removed is 'godlines'.
'godlines' is an anagram of 'longside'.
'longside' after 'a' is 'ALONGSIDE'.
(Other definitions for alongside that I've seen before include "Bordering" , "Age-old sin (anag.)" , "Next to - alien dogs (anag)" , "Side by side" , "Aligned so as to be close to pier" .)