Sulku

Sulku is a Finnish noun derived from the verb sulkea, meaning "to close." It denotes a closure, interruption, or device that closes or seals a passage, as well as the act of closing itself. The term is used in both everyday language and technical contexts.

Mechanical and technical usage: In engineering and plumbing, a sulku may refer to a shut-off device such as a valve or switch that stops the flow of liquid, gas, or electrical current. In many compound terms, sulku indicates a function or mechanism that closes a circuit or pathway, for example sulkuventtiili (shut-off valve).

Typography and writing: In Finnish typography, sulku refers to an enclosure mark, such as parentheses or brackets. The plural sulut covers the various enclosing marks used in text.

Other notes: As a common noun, sulku is widely understood in Finnish and appears in technical, industrial, and linguistic contexts. It can also form part of compound terms describing closures or barriers in systems and processes.