noun, masculine/tʁɔ̃ kɔ.mœ̃/plural: troncs communs
tronc commun is masculine in French.
core curriculum (courses or other components of an educational program which are foundational, prerequisite, or mandatory, as opposed to the elective, secondary, or variable components of a program)
“une matière du tronc commun” — a core course, a core subject
Calque of Latin truncus commūnis.