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Sea in Irish (Muir): Meaning, Pronunciation, Usage

The Irish for sea is muir, a feminine noun (plural mara).
Updated October 2026Report a mistake

How to say “sea” in Irish

Irish:
muir
English:
sea
Word type:
noun
Gender:
feminine, third declension
Pronunciation:
“mwir”  /mˠɪɾʲ/
Various forms
Plural:
mara (seas)
Genitive singular:
mara, na mara (e.g. leibhéal na mara, sea level)
Genitive plural:
mara, na mara (e.g. ainmhithe na mara, sea creatures)

What does “muir” mean?

sea
The large body of salt water covering much of the earth; a literary or formal word, often used in set phrases, beside the everyday 'farraige'.Also: ocean, the deep, main.

Other Irish words for sea: farraige (sea), lear (sea), aigéan (ocean)

“Muir” with the article

The plural of sea in Irish is mara. Here is muir after the article (an t-alt), in the singular and the plural.

an mhuir
the sea
Lenition: m becomes mh after an (feminine noun)
na mara
the seas
Plural: no change after na

“Muir” in a sentence: Irish examples

Common Irish sentences using muir, the Irish word for sea.

Ar muir is ar tír.
At sea and on land.
Bhí sé ar muir ar feadh fiche bliain.
He was at sea for twenty years.
Tá an teach cois mara.
The house is by the sea.
Is breá liom boladh na mara.
I love the smell of the sea.
Bhí an mhuir garbh inniu.
The sea was rough today.
Chuaigh siad thar muir go Meiriceá.
They went overseas to America.
Ithimid bia mara gach Aoine.
We eat seafood every Friday.

Other nouns in Irish

More everyday Irish nouns to learn next.

Sea in Irish: frequently asked questions

What is the Irish for sea?

The Irish for sea is muir (pronounced “mwir”). It’s a feminine noun and the plural is mara.

How do you pronounce muir in Irish?

Muir is said like “mwir” (IPA /mˠɪɾʲ/).

What is the plural of sea in Irish?

The plural of muir is mara; with the article, na mara means “the seas”. The genitive plural is mara, as in ainmhithe na mara (sea creatures).

Why does muir change to mhuir?

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

What is the difference between 'muir' and 'farraige'?

Both mean sea, but 'farraige' is the everyday word, while 'muir' is more literary and survives mainly in set phrases such as 'ar muir' (at sea) and the genitive 'mara' (bia mara, cois mara).

Why is 'mara' so common if 'muir' is rare?

The genitive 'mara' is used adjectivally in many everyday terms, such as 'bia mara' (seafood) and 'cois mara' (by the sea), even in speech that normally uses 'farraige'.

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