1. Must; ought; a defective verb, usually denoting promise, obligation, determination, or command.

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

• shaoe,
• shilf,
• shealf,
• shole,
• shaply,
• mashall,
• halll,
• sharly,
• shelll,
• shela,
• shile,
• shily,
• shirl,
• sahll,
• sheel,
• uhall,
• showl,
• shavel,
• shll,
• shalow

• shiloh,
• shawwal,
• Sheilah,
• Sheil,
• Shayla,
• shelley,
• shill,
• shealey,
• Shela,
• Sheely,
• shallow,
• Shelia,
• Shiela,
• shell,
• shull,
• Shelly,
• Shellie,
• Shyla,
• Shelli,
• shale,
• Shella,
• Sheila,
• Shaul,
• shyly,
• shoal,
• Shealy,
• shallu,
• shiley,
• sheeley,
• Shiel,
• shawl,
• sheley,
• Shila,
• shoaly,
• Shala.

The adverb form of "shall" is "shallingly".

The adjective form of "shall" is "shalling". However, this form is rarely used in modern English. Most often, "shall" is used as a modal verb indicating a future action or obligation.