What is the correct translation of the word Farth in the context of Surah An-Nahl, verse 66?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.

Al-Qurtubi said in his Tafseer, "Farth" is the excrement/feces while still in the belly.

Allah knows best.