カイ, ゲ, と.く, と.かす, と.ける, ほど.く, ほど.ける, わか.る, さと.る, さとる, とけ

unravel, notes, key, explanation, understanding, untie, undo, solve, answer, cancel, absolve, explain, minute

JLPT3 G5 S13 F176

角# horn + an element combining sword/knife and cow → *remove* cattle horns in butchering → *dismember*; *break*; *release*; *unravel*; *disentangle*; *untie*; *loosen*; *solve*; *melt* → *understand*; *explain* → *dispel* (← dispel doubts and obtain understanding) → *cancel*. *Comb* is by extension from "disentangle".

[Full Kanji Etymology List]