1. That can not be counted.

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

• countreis,
• councles,
• countrese,
• countlesss,
• coutnless,
• countelss,
• pontless,
• countreys,
• dountless,
• cuntless,
• counclers,
• countlless,
• contless,
• counltess,
• coutless,
• countles,
• counless,
• counteless,
• countiers,
• foundless

• condyle,
• condolence,
• county line,
• condole,
• counts,
• Counties,
• cutlass,
• counsels,
• counters,
• countess.

The adjective form of "countless" is "countless".