留一手

留一手

Literally means:

reserve a skill

Actually means:

hold back a trick or two (in teaching a trade or skill); have card up one's sleeve

一手 refers to a certain skill or trade.

The phrase means reserving some skills or trades, or retaining certain energy or resources. It often implies reserving the most important or crucial part, just in case.

一手，指某种技能或本领。

留一手，指不把技能或本领全部拿出来。也指保留一定的精力或财力。往往指保留最重要或者最关键的部分，以防万一。