Thirteenth
Thirteenth (thẽr"tēnth`) , adjective
[From Thirteen: compare Anglo-Saxon þreóteóea.]
1.
Next in order after the twelfth; the third after the tenth; -- the ordinal of thirteen; as, the thirteenth day of the month.
2.
Constituting or being one of thirteen equal parts into which anything is divided.
Thirteenth , noun
1.
The quotient of a unit divided by thirteen; one of thirteen equal parts into which anything is divided.
2.
The next in order after the twelfth.
3.
(Music) The interval comprising an octave and a sixth.