1. The day of judgment.

2. The day of final judgment.

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

• doomday,
• doomsdays,
• doomesday,
• doomsaday,
• soomsday,
• xoomsday,
• coomsday,
• foomsday,
• doomseday,
• domsday,
• doosday,
• doomsdayy,
• doomsdey,
• boomsdas,
• doomesman,
• doomsdaye,
• dymday,
• Boomsda,
• Doomsdaie,
• Coomida

• domestic.

The adjective form of "doomsday" is "doomsday".

The plural of the "doomsday" can be the "doomsdays".

The singular of the "doomsday" can be the "doomsday".