思考
しこう · shikou · JLPT N1 · noun
idea
考 — old 老 (top) + 丂 phonetic
Originally written like 老 ('old'), 考 depicted an elderly person with long hair leaning on a cane, and the two characters were once interchangeable. Over time 考 specialized to mean 'deceased father' and later 'to examine, test, investigate,' with the bottom 丂 hinting at the sound.