If this refers to aviation mechanics, "Avtub" could be shorthand for Av iation Tub ing or a specific brand, and "Syelin" is a phonetic spelling of Cylinder . This would refer to pneumatic or hydraulic cylinders used in aircraft control systems.
Is this a term from a language other than English? avtub syelin
"Avtub Syelin," people began to say, not two names but the town's new verb: to avtub syelin, meaning to return what should be returned and to keep what should be kept. It described an action and a code: notice what you hold, give back what you must, and make room for tides. If this refers to aviation mechanics, "Avtub" could