Is it imposter “ or something that is fake that is not necessarily human? Can it be both about a person and a thing?
It is not a very common word in today's language. According to the dictionary definition:
Its meaning is "liar", which is a human. The word seems to be used at several places in the Japanese Bible translations.
Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son. (1 John 2:22, ESV)