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.
A single tear ran down her cheek.
Overcome with emotion, a trickle of tears spilled out.
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.