full-fat

The compound "full-fat" is a modern English formation from two native Germanic roots. "Full" derives from Proto-Germanic fullaz, tracing back to the Proto-Indo-European root pelə- meaning "to fill," which conveys a sense of completeness and lack of reduction. "Fat" originates from Proto-Germanic faitidaz ("fatted"), from the PIE root poid- ("to abound in water, milk, fat"), associated with richness and nourishment. The term emerged in the 20th century within nutritional and commercial contexts to distinguish whole dairy products from their reduced-fat or skimmed counterparts. Its logic is transparently literal: describing a product containing the full, unaltered complement of its natural fatty content, a meaning later extended figuratively to denote any uncompromised, rich, or intense experience.

Structure: full (complete) + fat (fatty substance) full: From Old English full, meaning "complete, entire, abundant." It functions as an intensifier/modifier in this compound. fat: From Old English fǣtt, meaning "fatty, plump." It functions as the core noun being modified.