愚か
おろか · oroka · JLPT N1 · na-adj
foolish
愚 = 心 (mind/heart) + 禺 (sound part): a mind that goes off track is foolish
The kanji 愚 has the 心 heart/mind radical at its base, pointing to poor judgment. Oroka is the native Japanese reading used in everyday speech for foolish or stupid.