succinylcholine Syllabification: (suc·ci·nyl·cho·line)Pronunciation: /ˈsəksənlˈkōlēn/Definition of succinylcholine noun Medicine a synthetic compound used as a short-acting muscle relaxant and local anesthetic. It is an ester of choline with succinic acid. succinylcholine in other Oxford dictionaries Definition of succinylcholine in the British & World English dictionary