The compound "vest-pocket" is a straightforward descriptive term from the late 19th century, directly combining two common nouns. "Vest," denoting a sleeveless garment, originates from the Latin vestis (clothing), while "pocket," meaning a small pouch, derives from a Germanic root for "bag." The term literally describes the small pocket sewn into a man's waistcoat or vest. Its meaning evolved metaphorically from this literal sense to describe any object of a conveniently small size, and further to characterize places or editions as being diminutive or compact, capturing the essence of portability and constrained space inherent in its original referent.

Structure: vest (garment) + pocket (small bag) - vest: From Old French 'veste' (garment, robe), from Latin 'vestis' (garment, clothing). Functions as a noun used attributively to specify a type. - pocket: From Anglo-Norman 'poket', a diminutive of 'poke' (bag, sack), of Germanic origin. Functions as a noun specifying the object.