Plant making American tin in that way (8)
I believe the answer is:
acanthus
'plant' is the definition.
(acanthus is a kind of plant)
'american tin in that way' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'tin' becomes 'can' (synonyms).
'in that way' becomes 'thus' (synonyms).
'a'+'can'+'thus'='ACANTHUS'
'making' acts as a link.
(Other definitions for acanthus that I've seen before include "Growth" , "Bush?" , "Carved ornament" , "Cash, aunt, for this plant" , "Plant with prickly leaves" .)