unidentifiable

adjectives

impossible to identify
unidentifiable
antonym
identifiable
is similar to
difficult to describe
"a haunting elusive odor"
elusive
is similar to
hard to pin down or identify
"an intangible feeling of impending disaster"
intangible
is similar to
not possible to classify
unclassifiable
is similar to
not possible to diagnose
undiagnosable
is similar to
defying recognition as e.g. because of damage or alteration
unrecognisable, unrecognizable