noun
drawn water; water drawn and left to stand
Water that has been drawn and set aside, often for drinking or household use. May imply it has been left to sit for a while.
汲み置きの水でお茶を入れた。
I made tea with water that had been drawn and left to stand.
夏は汲み置きの水がすぐぬるくなる。
In summer, drawn water quickly becomes lukewarm.
汲む is the verb meaning 'to draw (water)'; 汲み置き is the resulting water that has been drawn and set aside.
Compound of 汲み (kumi, continuative form of 汲む 'to draw water') + 置き (oki, continuative form of 置く 'to put/leave'). Literally 'drawing and leaving'.