expression, noun
halting speech; stammering
Idiomatic expression likening hesitant, slow speech to rainwater dripping off a horizontal board. Often used in contrast with 立て板に水 (fluent, rapid speech).
Antonyms: 立て板に水
彼のスピーチは横板に雨垂れのような話し方だった。
His speech was halting, like rainwater dripping off a horizontal board.
横板に雨垂れでは、聞いている方がもどかしい。
When someone speaks haltingly, it's frustrating for the listener.
Antonym: describes fluent, rapid speech, like water flowing down a vertical board.
The expression is a metaphorical phrase; its origin is uncertain, but it vividly compares slow, hesitant speech to the irregular dripping of rainwater from a horizontal board.