What does "blacken" mean?

To cause to be or become black.

What is a synonym for "blacken"?

Common synonyms include: black, black, defame, dirty, denigrate, befoul.

//ˈblækən// verb

verb ·Common ·High school level

Verb

1
To cause to be or become black. causative, transitive
"Iron and coal were the magnets that drew railways to this land of lovely valleys and silent mountains—for such it was a century-and-a-half ago, before man blackened the valleys with the smoke of his forges, scarred the green hills with his shafts and waste-heaps, and drove the salmon from the quiet Rhondda and the murmuring Taff."
2
make or become black wordnet
3
To become black. ergative, intransitive
"The sky blackened as the storm clouds rolled in."
4
burn slightly and superficially so as to affect color wordnet
5
To make dirty. causative, transitive

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6
To defame or sully.
7
To cook (meat or fish) by coating with pepper, etc., and quickly searing in a hot pan. transitive

"Hundreds of years ago, married Japanese women would blacken their teeth to beautify themselves."

From Middle English blaknen, blakkenen, equivalent to black + -en (verbal suffix).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.