1. The state of being tired.

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

• tardness,
• tierdness,
• tirdness,
• tirdyness,
• tireness,
• tiredless,
• triedness,
• tirednes,
• boredness,
• toredness,
• tiresness,
• tirednesse,
• tirdeness,
• tyredness,
• tirelness,
• topedress,
• piedneses,
• thrediness,
• Cervedness,
• retredness

The adjective form of "tiredness" is "tired".

The plural of the "tiredness" can be the "tirednesses".

The singular of the "tiredness" can be the "tiredness".