Almost always appears in compounds: 痉挛 (jìngluán, spasm/convulsion), 抽痉 (chōujìng, to cramp), 热痉 (heat cramps). Standalone use is rare in modern Chinese.
memory
Sickness radical 疒 + 巠 (jīng) — a sick body part being pulled tight; 巠 also gives the pronunciation.
