Fewmets

From the real English word 'fewmets' meaning deer droppings (a term from hunting). McCaffrey repurposed it for dragon excrement, and because dragonriders work with it daily, it naturally became their go-to scatological curse.

Used across the Pern novel series. Notable because it's based on a real (if archaic) English word.

A realistic example of profession-specific profanity. The people who deal with the substance daily are the ones who curse with it.

Consistent usage throughout the series. A term of art that doubled as profanity.

Specific to dragonrider culture. Non-riders might not use it.