also: にせちち
noun
fake breasts; artificial breasts
Slang term for breast forms, padded bras, or any artificial breasts, often used in casual or humorous contexts.
コスプレ用の偽乳を買った。
I bought fake breasts for cosplay.
あのアイドル、偽乳使ってるんじゃない?
That idol might be using fake breasts, don't you think?
Compound of 偽 (false, fake) and 乳 (breasts). The reading ぎにゅう uses the on'yomi of both kanji, while にせちち uses the kun'yomi of 偽 and the kun'yomi of 乳.