1. Silently; without words or speech.

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

• fambly,
• deebly,
• sumble,
• dumbas,
• dimily,
• duble,
• humbaly,
• dumbe,
• humbily,
• jumbly,
• damily,
• rumbly,
• dumbo,
• dumby,
• doubbly,
• humblly,
• dumbell,
• dummby,
• umble,
• dimely

• dumber,
• Dimply,
• fumble,
• dumbleton,
• mumble,
• rumble,
• humble,
• tumble,
• dumbbell,
• humbly,
• jumble.

The adjective form of "dumbly" is "dumb".

The plural form of the word "dumbly" is still "dumbly." It does not change in the plural.

The singular form of the word "dumbly" is "dumbly". This word does not change in its form when used in the singular.