Asymmetrical meter is a rhythmic structure that does not conform to traditional, even subdivisions of beats, often resulting in groupings of unequal lengths. This creates a unique, unpredictable feel in music, distinguishing it from symmetrical meters like 4/4 or 3/4. Asymmetrical meter is characterized by combinations of different beat values, leading to varied accents and phrases that can enhance the complexity and expressiveness of a piece.