The word 偶尔 is formed by combining two characters: 偶, which originally meant a wooden or clay human figurine and by extension conveys the idea of something incidental, paired, or by chance; and 尔, an ancient literary word meaning "such" or "like this". Together, they create a conceptual blend where 偶 provides the core meaning of "occasional" or "unexpected", and 尔 subtly reinforces it as "in such a manner", resulting in a compound that poetically encapsulates the sense of "once in a while" or "as an occasional occurrence".