To frighten someone suddenly.
From Old Norse 'skirra', meaning to frighten or to avoid, related to 'skjarr' meaning timid or shy. The word came into English through Scandinavian influence during the Viking age. It is related to the word 'scarecrow'.
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Smooth and glossy, or done in a clever and effortless way.
Probably from Old Norse 'slíkr' meaning smooth, or related to Old English 'slician' meaning to make smooth. It is thought to share roots with 'sleek,' which has a similar meaning. The word has long described smooth surfaces and, later, smooth performances.
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