1. To grow black or dark.

2. To make black; to darken; to sully; to make infamous.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• blackl,
• blocken,
• blackend,
• baken,
• brocken,
• blanken,
• blatten,
• blackbun,
• blacket,
• blaiten,
• backin,
• borcken,
• backon,
• becken,
• blakent,
• blacknes,
• lackin,
• blaziken,
• blackes,
• slarken

• Blackener,
• Bligen,
• bleakness,
• black knot,
• Blakeney,
• blacking,
• black man,
• blackmon,
• blackens,
• blackened,
• blacksnake,
• blackening,
• blackness,
• blakemore,
• blackmore,
• black hand,
• blacker,
• blackson,
• black swan,
• black,
• blackman,
• Blixen,
• blackmer,
• blackmail,
• blocking,
• Blakeman,
• black gum,
• blechnum.

The adverb form of "blacken" is "blackenly", although it is not commonly used. A more commonly used adverb is "darkly".

The adjective form of the word "blacken" is "blackened".

The plural form of the word "blacken" is "blackens"

The singular form of the word "blacken" remains the same, as it is already in its base form.