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Cause in Irish (Cúis): Meaning, Pronunciation, Usage

‘cúis’ also means: reason · case

The Irish for cause is cúis, a feminine noun (plural cúiseanna).
Updated October 2026Report a mistake

How to say “cause” in Irish

Irish:
cúis
English:
cause, reason, case
Word type:
noun
Gender:
feminine, second declension
Pronunciation:
“koosh”  /kuːʃ/
Various forms
Plural:
cúiseanna (causes)
Genitive singular:
cúise, na cúise (e.g. cúlra na cúise, the background of the cause)
Genitive plural:
cúiseanna, na gcúiseanna (e.g. liosta na gcúiseanna, a list of reasons)

What does “cúis” mean?

“Cúis” has four alternative meanings. The most common comes first.

cause
The thing that makes something happen.Also: source, origin.
3 other meanings: reason or case
2reason
The explanation or grounds for something.Also: grounds, motive.
3case
A matter or lawsuit brought before a court.Also: lawsuit, legal case.
4cause
A movement or principle that people support.Also: movement, campaign.

Other Irish words for cause: fáth (reason)

“Cúis” with the article

The plural of cause in Irish is cúiseanna. Here is cúis after the article (an t-alt), in the singular and the plural.

an chúis
the cause
Lenition: c becomes ch after an (feminine noun)
na cúiseanna
the causes
Plural: no change after na

“Cúis” in a sentence: Irish examples

Common Irish sentences using cúis, the Irish word for cause.

Is cúis imní í sin dom.
That's a cause of worry for me.
Cad é an chúis go bhfuil tú déanach?
What's the reason you're late?
Mhínigh sí na cúiseanna dom.
She explained the reasons to me.
Níl aon chúis gearáin agam.
I have no reason to complain.
Cad is cúis leis an tine?
What caused the fire?
Bhí an chúis os comhair na cúirte inné.
The case was before the court yesterday.
Dhéanfadh leath an méid sin cúis.
Half of that amount would do.

Other nouns in Irish

More everyday Irish nouns to learn next.

Cause in Irish: frequently asked questions

What is the Irish for cause?

The Irish for cause is cúis (pronounced “koosh”). It’s a feminine noun and the plural is cúiseanna. Depending on context it can also mean reason or case.

How do you pronounce cúis in Irish?

Cúis is said like “koosh” (IPA /kuːʃ/).

What is the plural of cause in Irish?

The plural of cúis is cúiseanna; with the article, na cúiseanna means “the causes”. The genitive plural is cúiseanna, as in liosta na gcúiseanna (a list of reasons).

Does cúis have more than one meaning?

Yes. Cúis can mean cause, reason or case, depending on context; the first is the most common.

Why does cúis change to chúis or gcúis?

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

What is the difference between cúis and fáth?

Both mean reason, but fáth is the usual word in questions like 'Cén fáth?', while cúis also means cause, a legal case or a cause people support.

What does 'déanfaidh sé cúis' mean?

It is an idiom meaning 'it will do' or 'it will suffice'.

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