1. The ordinal of thirteen; being one of thirteen equal parts.

2. One of thirteen equal parts; an interval forming the octave of the sixth.

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

• thirtienth,
• thirtenth,
• thriteenth,
• thirteenat,
• thirdtenth,
• thirtheenth,
• thirteeth,
• thiteenth,
• thirtheeeth,
• thirthenth,
• rhirteenth,
• fhirteenth,
• ghirteenth,
• thurteenth,
• thirteentjh,
• thirteent,
• tihrteenth,
• thirtent,
• thirtentn,
• thirtenith

• threaten,
• thirteen,
• threatened,
• thirty-ninth,
• threateningly,
• threatening.

The adjective form of the word "thirteenth" is "thirteenth".

The plural form of the word "thirteenth" is "thirteenths"

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