na-adjective, noun which may take the genitive case particle 'no', prefix
Used as a prefix or adjectival noun to describe something that is not genuine, often in technical or formal contexts (e.g., 偽性アルカローシス 'pseudoalkalosis').
偽性アルカローシスは、実際にはアルカローシスではない状態を指す。
Pseudoalkalosis refers to a condition that is not actually alkalosis.
この素材は偽性皮革で、本物の革ではない。
This material is imitation leather, not real leather.
疑似 (ぎじ) also means 'pseudo-' or 'simulated', but is more common in everyday and technical terms (e.g., 疑似科学 'pseudoscience'). 偽性 (ぎせい) is rarer and tends to appear in specialized medical or technical vocabulary.
Compound of 偽 (ぎ, 'false') and 性 (せい, 'nature, quality'), literally 'false nature'. The spelling 偽製 uses 製 (せい, 'made') suggesting 'falsely made', but 偽性 is the more common form.