adventitious

adjectives

associated by chance and not an integral part
"poetry is something to which words are the accidental, not by any means the essential form"- Frederick W. Robertson; "they had to decide whether his misconduct was adventitious or the result of a flaw in his character"
adventitious
is similar to
not forming an essential part of a thing or arising or originating from the outside
"extrinsic evidence"; "an extrinsic feature of the new building"; "that style is something extrinsic to the subject"; "looking for extrinsic aid"
extrinsic