gachi-gachi
Something completely hardened and rigid — frozen solid, or a person stiff with cold or nervousness. Stronger than kachi-kachi.
💡Frozen pipes in winter — 'The water pipes are gachi-gachi frozen.'
寒さで体ががちがちに固まった。
My body went gachi-gachi stiff from the cold.
I was so nervous my shoulders were ___ with tension.
緊張で肩が○○に固まっていた。