trigesimal

English

Etymology

From Latin trigesimus (“thirtieth”) + -al (“forming adjectives”).

Adjective

trigesimal (not comparable)

1. (obsolete) Thirtieth.

   In the trigesimal year of his reign...

2. (rare) Containing thirty of something.

   Each month is a roughly trigesimal period.

Noun

trigesimal (uncountable)

1. The trigesimal number system; base 30.

References

• Oxford English Dictionary, "trigesimal, adj."