1. Which of two alternatives, expressed by a sentence or the clause of a sentence, and followed by or; as, "resolve whether you will go or not".

2. Which of two.

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

• waether,
• whwether,
• niether,
• whenthe,
• wherher,
• wheth,
• waither,
• ohther,
• whiether,
• weeather,
• whetether,
• wethr,
• weter,
• whenthey,
• whetheror,
• wheer,
• waethers,
• whteher,
• whtether,
• whenther

• whittier,
• wether,
• whitehair,
• whither.

The adjective form of the word "whether" is "whethering".

The plural form of the word "whether" is "whethers." However, it is rarely used in the plural form, as "whether" is primarily used as a conjunction or adverb and does not typically require a plural.

The singular form of the word "Whether" is "Whether". It does not have a distinct singular form as it is already singular.