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Third in Irish (Tríú): Meaning, Pronunciation, Usage

The Irish for third is tríú, a masculine noun (plural tríthe).
Updated October 2026Report a mistake

How to say “third” in Irish

Irish:
tríú
English:
third
Word type:
noun
Gender:
masculine, fourth declension
Pronunciation:
“TREE-oo”  /tʲɾʲiːuː/
Various forms
Plural:
tríthe (thirds)
Genitive singular:
tríú, an tríú (e.g. duais an tríú, the third's prize)
Genitive plural:
tríthe, na dtríthe (e.g. suim na dtríthe, the sum of the thirds)

What does “tríú” mean?

third
A third part of something, one of three equal parts; also the third in a series.Also: third part, one third.

Other Irish words for third: trian (third)

“Tríú” with the article

The plural of third in Irish is tríthe. Here is tríú after the article (an t-alt), in the singular and the plural.

an tríú
the third
No change after an
na tríthe
the thirds
Plural: no change after na

“Tríú” in a sentence: Irish examples

Common Irish sentences using tríú, the Irish word for third.

Bhuaigh mé an tríú duais.
I won the third prize.
Is mise an tríú duine sa chlann.
I am the third child in the family.
Coláiste tríú leibhéal é.
It is a third-level college.
Tá tríú den chíste fágtha fós.
A third of the cake is still left.
Roinn sé an talamh ina thríthe.
He divided the land into thirds.
Fuair gach duine tríú den airgead.
Everyone got a third of the money.
Sin an tríú huair inniu.
That's the third time today.

Other nouns in Irish

More everyday Irish nouns to learn next.

Third in Irish: frequently asked questions

What is the Irish for third?

The Irish for third is tríú (pronounced “TREE-oo”). It’s a masculine noun and the plural is tríthe.

How do you pronounce tríú in Irish?

Tríú is said like “TREE-oo” (IPA /tʲɾʲiːuː/).

What is the plural of third in Irish?

The plural of tríú is tríthe; with the article, na tríthe means “the thirds”. The genitive plural is tríthe, as in suim na dtríthe (the sum of the thirds).

Why does tríú change to thríú or dtríú?

Irish changes the start of some words after certain words. After mo (my) tríú becomes mo thríú (lenition), and after ár (our) or i (in) it becomes ár dtríú (eclipsis).

What is the difference between 'tríú' and 'trian'?

'Tríú' is mainly the ordinal 'third' (an tríú lá, the third day), while 'trian' is the usual noun for a fraction, one third (trian den airgead). 'Tríú' is also used for the fraction, as in 'tríú den chíste'.

Does 'tríú' cause a mutation?

After 'an tríú', a following noun beginning with a vowel takes h: an tríú huair, the third time.

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