How do you say papyrus in french?

It's 'papyrus' (masculine noun) in French, and is pronounced thus:

/papiʀys/

If you can't read IPA, it's like pah-pee-rus

The 'ah' is pronounced with the back of your throat, like English people saying 'farm' or 'half.'

The 'u' in 'rus' is sort of 'high-pitched,' and not made with rounded lips: it's the same as that found in in French 'tu' (or in English, sometimes similar to 'cute'), as opposed to the rounded 'ou' sound in 'vous.'