The word is a modern English compound formed by directly combining the Latin prefix 'sub-' with the noun 'cabinet'. 'Cabinet' itself has a fascinating journey, originating from the Old French 'cabane' (hut), via Italian 'gabinetto' (a small room), evolving to mean a private council chamber and then the group of ministers meeting there. The prefix 'sub-', from Latin 'sub' (under), is a prolific element in English, consistently conveying the sense of being lower in rank or position. Therefore, 'sub-cabinet' logically constructs its meaning from its parts: pertaining to the level immediately beneath the official cabinet.

Structure: sub (under) + cabinet (a body of high-ranking officials) - sub: Latin origin, a prefix meaning "under, below, or secondary." - cabinet: French origin, from Italian 'gabinetto', meaning a small private room; its role in the word is the core noun, denoting the group of high-ranking officials.