Home established finally by American river (5)
I believe the answer is:
indus
'river' is the definition.
(Indus is an example)
'home established finally by american' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'finally' says to take the final letters.
'by' means one lot of letters go next to another.
'american' becomes 'us'.
The last letter of 'established' is 'd'.
'in'+'d'+'us'='INDUS'
(Other definitions for indus that I've seen before include "South Asian river" , "9 of Pakistan" , "Great river of South Asia" , "Sacred flower" , "River of Southern Asia" .)