飲のみ込こみが早はやい

Meanings

1

expression, i-adjective

Describes a person who grasps new concepts, instructions, or situations rapidly. Often used as a compliment.

飲のみ込こみが早はやい人ひとは、説せつ明めいが一いち度どで済すむ。

A quick-witted person only needs to be told once.

飲のみ込こみが早はやい
Standard kanji spelling using 飲.
呑のみ込こみが早はやい
Variant using 呑, which can carry a nuance of swallowing whole or grasping quickly.
のみ込こみが早はやい
Kana spelling for the first part; common in casual writing.

頭あたまがいい
Refers to general intelligence or being smart, while 飲み込みが早い specifically highlights the speed of understanding or catching on.
勘かんがいい
Means having good intuition or a sharp sixth sense, whereas 飲み込みが早い focuses on quick comprehension of explained or observed information.

From 飲み込む (to swallow, to understand) + が早い (is fast). The metaphor is of quickly 'swallowing' or internalizing information.