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Definition in Irish (Sainiú): Meaning, Pronunciation, Usage

The Irish for definition is sainiú, a masculine noun (plural sainithe). Ag sainiú is defining, from the verb sainigh.
Updated October 2026Report a mistake

How to say “definition” in Irish

Irish:
sainiú
English:
definition
Word type:
noun (verbal noun)
Verbal noun of:
sainigh, to define (ag sainiú, defining)
Gender:
masculine
Pronunciation:
“SAN-yoo”  /ˈsˠanʲuː/
Various forms
Plural:
sainithe (definitions)
Genitive singular:
sainithe, an tsainithe (e.g. próiseas an tsainithe, the process of definition)
Genitive plural:
sainithe, na sainithe (e.g. bailiúchán na sainithe, the collection of definitions)

What does “sainiú” mean?

definition
The act of stating exactly what something means or what its limits are; verbal noun of the verb 'sainigh' (define).Also: defining, specification, specifying.

“Sainiú” as a verbal noun

After ag, sainiú means defining: it is the verbal noun of the verb sainigh (to define). A noun that follows it goes into the genitive.

agat
+
sainiúverbal noun
=
ag sainiúdefining

“Sainiú” with the article

The plural of definition in Irish is sainithe. Here is sainiú after the article (an t-alt), in the singular and the plural.

an sainiú
the definition
No change after an
na sainithe
the definitions
Plural: no change after na

“Sainiú” in a sentence: Irish examples

Common Irish sentences using sainiú, the Irish word for definition.

Tá sainiú soiléir ag teastáil don téarma seo.
This term needs a clear definition.
Níl an sainiú san fhoclóir ceart.
The definition in the dictionary is not correct.
Tá na sainithe sa dlí an-chasta.
The definitions in the law are very complicated.
Is deacair sainiú a thabhairt ar an ngrá.
It is hard to define love.
Léigh mé sainiú an fhocail sa leabhar.
I read the definition of the word in the book.
Tá ailt shainithe ag tús an Achta.
There are definition sections at the start of the Act.
Ní aontaím le do shainiú ar an bhfadhb.
I don't agree with your definition of the problem.

Other nouns in Irish

More everyday Irish nouns to learn next.

Definition in Irish: frequently asked questions

What is the Irish for definition?

The Irish for definition is sainiú (pronounced “SAN-yoo”). It’s a masculine noun and the plural is sainithe.

How do you pronounce sainiú in Irish?

Sainiú is said like “SAN-yoo” (IPA /ˈsˠanʲuː/).

What is the plural of definition in Irish?

The plural of sainiú is sainithe; with the article, na sainithe means “the definitions”. The genitive plural is sainithe, as in bailiúchán na sainithe (the collection of definitions).

Why does sainiú change to shainiú?

After words like mo (my) and do (your) the first letter is lenited: mo shainiú. After ár (our) it stays ár sainiú, because s does not take eclipsis.

What is the difference between 'sainiú' and 'sainmhíniú'?

Both can translate 'definition'; 'sainmhíniú' is the usual word for a dictionary or formal definition, while 'sainiú' stresses the act of defining or specifying.

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