留后手

Traditional (Taiwan): 留後手

liúhòushǒu ㄌㄧㄡˊ ㄏㄡˋ ㄕㄡˇ

    • to hold something back in reserve
    • to keep an option open for later

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
keep a move in reserve
Meaning
To hold something back in advance so as not to be left helpless later. Somewhat cautious or guarded.

Sources