• nighclub,
• nigthclub,
• lightblub,
• bightclub,
• mightclub,
• jightclub,
• hightclub,
• nughtclub,
• njghtclub,
• nkghtclub,
• noghtclub,
• n9ghtclub,
• n8ghtclub,
• nifhtclub,
• nivhtclub,
• nightclyb,
• night clup,
• nitclub,
• nightcalub,
• nightclueb

• nightcap,
• night-stop,
• nightcrawler,
• nightclothes,
• night soil,
• nightspot,
• nightshirt,
• night school.

"Nightclub" is already an adjective, as it describes a type of club or establishment that is primarily active during the night.

The plural of the "nightclub" can be the "nightclubs".

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