expression, noun
a trickle of tears; a single tear
A set phrase describing a single line of tears flowing down the cheek, often used in emotional or poetic contexts.
彼女の頬を一筋の涙が伝った。
A single tear ran down her cheek.
感動のあまり、一筋の涙がこぼれた。
Overcome with emotion, a trickle of tears spilled out.
一粒の涙 emphasizes a single teardrop, whereas 一筋の涙 focuses on the flowing line of tears.
A set phrase composed of 一筋 (one line, a single streak) and 涙 (tears). The exact historical origin is uncertain, but it is a conventional expression in Japanese literature.