がっくり
がっくり · gakkuri · JLPT N1 · adverb
heartbroken
💔 がっくり sounds like 'gakku' (a tumble) + 'ri': the heart drops with a thud, a broken-heart 💔 moment.
がっくり is onomatopoeia for sudden collapse of spirits. Its 'gakku' sound mimics a sudden drop or slump, so hearing it signals a heart that has fallen hard.