Sky and Welkin

Sky noun – The expanse of air surrounding the earth.

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Welkin is a synonym for sky in heavens topic. In some cases you can use "Welkin" instead a noun "Sky", when it comes to topics like high. literary substitute

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Nearby Words: skyline, skyway, skying, skye, skyer

Welkin noun – The apparent surface of the imaginary sphere on which celestial bodies appear to be projected.

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Sky is a synonym for welkin in high topic. You can use "Sky" instead a noun "Welkin", if it concerns topics such as air.