偽(にせ)

Works both as a noun and as a prefix on other nouns.

Compounds

• 偽(にせ)もの: fake item, counterfeit
• 偽(にせ)札(さつ): counterfeit money/bills
• 偽(にせ)ブランド: counterfeit brand goods
• 偽(にせ)医者(いしゃ): fake doctor, quack
• 偽(にせ)情報(じょうほう): false information

Similar words

• 偽物(にせもの): counterfeit, imitation (the noun form)
• 贋作(がんさく): forgery (specifically of art or antiques)
• フェイク: fake (loanword, common in fashion and media)
• 模造品(もぞうひん): imitation product (neutral; focuses on the copying)

本物(ほんもの) (the real thing, genuine article) is the opposite of 偽物(にせもの). The pattern 本物(ほんもの)か偽物(にせもの)か (real or fake?) is very common.

Watch out

Some compounds read the kanji ぎ instead: 偽名(ぎめい) (false name), 偽造(ぎぞう) (forgery), 偽装(ぎそう) (disguise, falsification).