The story
- Proto-Indo-European*mel-
- Proto-Indo-European*ml̥tós?
- Proto-Italic*moltos
- Latinmultus
- Latinmultī
- Middle Englishmulti-
- Englishmulti-
- Proto-Indo-European*ḱe?
- Proto-Indo-European*ḱóm
- Proto-Italic*kom
- Proto-Italic*kom-
- Latincom-
- Proto-Indo-European*perh₃-
- Proto-Indo-European*pérh₃tis?
- Proto-Italic*partis
- Latinpars
- Latinpartiō
- Latinpartior
- Latincompartīrī
- Italiancompartire
- Italiancompartimento
- Middle Frenchcompartiment
- Englishcompartment
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- English todaymulticompartmental
By surface analysis, multi- + compartment + -al.
Etymology from Wiktionary, CC BY-SA 4.0.