1. Unchangeably.

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

• immutible,
• imutable,
• ijmmutable,
• ummutably,
• jmmutably,
• kmmutably,
• ommutably,
• 9mmutably,
• imnutably,
• imutably,
• immitancy,
• immitiably,
• impuably,
• imputtably,
• incmmutably,
• immunably,
• Impultably,
• immentably,
• immutalbly,
• immutibuly

• immutable,
• immutability.

The plural form of the word "immutably" is "immutablys." However, it is worth noting that the word "immutably" is not commonly used in the plural form.

The singular form of the word "immutably" is "immutability"