Meaning

noun a vertical structure that divides or separates (as a wall divides one room from another)

noun (computer science) the part of a hard disk that is dedicated to a particular operating system or application and accessed as a single unit

noun (anatomy) a structure that separates areas in an organism

originRecorded c.1430, "division into shares, distinction," from Middle English particioun, from Old French particion (modern partition), from Latin partitio, partitionem (“division, portion”), from partitus, the past participle of partire (“to split (up), part(ition)”).

Etymology from Wiktionary, CC BY-SA 3.0