i-adjective
not through; not finished; not done
Negative form of 切る (to cut), used in compound verbs to mean an action is not completed or not done thoroughly. Often follows the continuative form of another verb.
この本はまだ読み切らない。
I haven't finished reading this book yet.
彼は最後まで走り切らなかった。
He didn't run all the way to the end.
切る is the base verb meaning 'to cut' or, as a suffix, 'to do completely'. 切らない is its negative form.
Negative form of 切る (kiru), from the verb stem 切り (kiri) + negative auxiliary ない (nai). The kanji spelling 切ら無い is an ateji usage of 無 for the negative.