stump; cut-off stake
Refers to a stake or post that has been cut short, often driven into the ground; can also mean a tree stump.
庭に切り杭が何本も残っている。
Several stumps remain in the garden.
古い柵の切り杭を抜くのは大変だ。
It's hard work pulling out the old fence's cut-off stakes.
Compound of 切り (kiri, 'cutting') + 杭 (kui, 'stake'). The reading きりくい is a straightforward combination of the kun'yomi readings of the two kanji.