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Deadly in Irish (marfach): Meaning, Forms, Examples

Other uses of ‘marfach’: deadly boring

The Irish for deadly is marfach: galar marfach, a deadly disease.
Updated October 2026Report a mistake

How to say “deadly” in Irish

Irish:
marfach
English:
deadly, deadly boring
Word type:
adjective
Deadlier:
níos marfaí
Deadliest:
is marfaí
Plural:
marfacha
Pronunciation:
“MAR-uh-fukh”  /ˈmˠaɾˠəfˠəx/

What does “marfach” mean?

“Marfach” has two alternative meanings. The most common comes first.

deadly
Able to cause death; fatal or lethal.Also: fatal, lethal, mortal, killing.
1 other meaning: deadly boring
2deadly boring
Extremely tiresome, tedious or hard to bear, used figuratively.Also: tedious, tiresome, killing.

“Marfach” after a noun

An Irish adjective comes after its noun. Here is marfach after galar (disease, masculine), after scian (knife, feminine) and after a plural.

after a masculine noungalar marfacha deadly disease
after a feminine nounscian mharfacha deadly knife
after a plural noungalair mharfachadeadly diseases

séimhiú (the h) the ending

feminine
scianknife
+
marfachdeadly
=
scian mharfacha deadly knife

After a feminine noun the adjective gets a séimhiú, an h after its first letter: scian mharfach. After a masculine noun it stays as it is: galar marfach.

plural
galairdiseases
+
marfachadeadly, plural
=
galair mharfachadeadly diseases

With a plural noun the adjective takes its plural form, marfacha. It also gets an h after a plural that ends in a slender consonant: galair mharfacha; after other plurals it does not: sceana marfacha.

Deadlier, deadliest, very deadly

níosmore
+
marfaídeadly
=
níos marfaídeadlier
ismost
+
marfaídeadly
=
is marfaídeadliest

Tá an víreas seo níos marfaí ná an ceann eile. This virus is deadlier than the other one.

deadlierníos marfaíin the past tense: ní ba mharfaí
deadliestis marfaíin the past tense: ba mharfaí
as deadly aschomh marfach leno change after chomh
very deadlyan-mharfachan- lenites, except d, t and s
too deadlyrómharfachró- lenites

“Marfach” in a sentence: Irish examples

With a masculine noun, a feminine noun, a plural, a comparison and on its own.

Is galar marfach í an ailse.
Cancer is a deadly disease.
Tá nimh mharfach sa bhuidéal sin.
There is deadly poison in that bottle.
Bhí na tonnta marfach ar an gcósta sin.
The waves were deadly on that coast.
Tá an víreas seo níos marfaí ná an ceann eile.
This virus is deadlier than the other one.
Tá an nathair sin marfach.
That snake is deadly.

Other adjectives in Irish

More everyday Irish adjectives to learn next.

Deadly in Irish: frequently asked questions

What is the Irish for deadly?

The Irish for deadly is marfach (pronounced “MAR-uh-fukh”). It comes after the noun: galar marfach, a deadly disease; scian mharfach, a deadly knife.

How do you say deadlier and deadliest in Irish?

níos marfaí is deadlier and is marfaí is deadliest. In the past tense they become ní ba mharfaí and ba mharfaí.

Why does marfach become mharfach?

After a feminine singular noun an adjective is lenited: it gets an h after its first letter. So scian mharfach (a deadly knife) but galar marfach (a deadly disease), because galar is masculine.

What is the plural of marfach?

With a plural noun marfach becomes marfacha: galair mharfacha, sceana marfacha. After a plural that ends in a slender consonant it is lenited as well.

How do you say very deadly in Irish?

an-mharfach. Too deadly is rómharfach, and as deadly as is chomh marfach le.

Does marfach have more than one meaning?

Yes. Marfach can mean deadly or deadly boring, depending on context; the first is the most common.

What is the difference between 'marfach' and 'básmhar'?

'Marfach' means deadly or causing death, as in 'galar marfach', while 'básmhar' means mortal in the sense of subject to death, as in 'is duine básmhar é'.

How do you say 'mortal sin' in Irish?

A mortal sin is 'peaca marfach', the opposite of a venial sin, 'peaca solathach'.

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