• adulatadulta,
• adultaudlt,
• addultaddult

• adulterate,
• adulterous,
• adulterating,
• adulterated,
• adulteress,
• adultery,
• adulterant,
• Adultness,
• adulthood.

The adjective form of the word "adult" is actually "adult". The word "adult" can function as both a noun and an adjective.

The plural form of the word "adultadult" is "adultadults".

The singular form of the word "adultadult" is still "adultadult" as it is not a commonly used word and does not have a recognized singular form.