Refers to someone in a higher position within an organization, such as a boss, manager, or senior colleague. More formal than 上司.
Please proceed with the procedure after obtaining approval from your superior.
彼は私の直属の上長です。
He is my direct superior.
Compound of 上 (じょう, 'upper') and 長 (ちょう, 'head' or 'chief'). The reading じょうちょう is a standard on'yomi combination.