1. That may be believed.

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

• belivable,
• beliveble,
• believebly,
• beliavable,
• belivible,
• beleievable,
• believabel,
• umbelievable,
• believeably,
• beliviable,
• beievable,
• believible,
• beilivable,
• ubelievable,
• believeble,
• believle,
• believiable,
• beilevable,
• beleivable,
• inbelievable

• believability,
• believably.

The adjective form of the word "believable" is "credible".

The plural form of the word "believable" is "believables".

The singular form of the word "believable" is "believable".