suxamethonium chloride UK /ˌsʌk.sə.mɪˌθəʊ.ni.əm ˈklɔː.ɹʌɪd/US /ˌsʌk.sə.məˌθoʊ.ni.əm ˈklɔɹˌaɪd/ noun1 •A basic synthetic compound used intravenously chiefly in the hydrated form C₁₄H₃₀Cl₂N₂O₄·2H₂O as a short-acting muscle relaxant and local anesthetic. It is an ester of choline with succinic acid.