The eyelashes around your eye, or whip-like strokes used as punishment; can also mean to tie something down tightly.
From Middle English 'lasche,' possibly from Old Norse 'löskr' (loose) or imitative in origin, mimicking the sound of a whip striking. The connection to eyelashes is metaphorical—they 'lash' or flick like a whip.
Your eyelashes actually protect your eyes by sensing air movement and triggering a blink reflex, so calling them 'lashes' because they look whip-like is poetic—nature named them first, then we realized the comparison.
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