Superlative form of little, meaning the smallest in size, amount, or degree among three or more items.
From Old English lytel with the superlative suffix -est. The word 'little' comes from Proto-Germanic luttila. English uniquely uses both 'littlest' and 'smallest' as superlatives, whereas most languages have only one form.
English is unusual in having two superlative forms for small: 'smallest' (from Germanic) and 'littlest' (also Germanic but different root). Most languages would pick one, but English kept both, with 'littlest' often sounding more affectionate - think 'my littlest finger' versus 'my smallest finger'.
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