Superlative form of dim; the least bright or the most unclear, obscure, or difficult to perceive.
From dim + -est (superlative suffix). Old English 'dim' has Germanic roots; the superlative form follows standard English patterns.
The dimmest light often reveals the most—astronomers discovered dark matter by studying the dimmest galaxies, showing that sometimes the least obvious things teach us the most about the universe.
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