rimless

The word is a modern English compound formed by combining the noun "rim," a word of Old English origin meaning "border" or "edge," with the adjectival suffix "-less," also from Old English, meaning "devoid of." The term "rim" itself can be traced back to Proto-Germanic rimô, related to the concept of a raised strip or border. The straightforward compounding logic, "without a rim," directly yields the contemporary meaning, specifically describing eyewear whose lenses are not encircled by a traditional frame. This transparent construction exemplifies how English readily creates descriptive adjectives by attaching the productive suffix "-less" to a concrete noun.

Structure: rim (edge) + less (without) - rim: From Old English rima (border, edge, coast). A noun-forming element denoting a raised or defining edge. - less: From Old English -lēas (devoid of, free from). An adjective-forming suffix meaning "without."