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

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

How to say “deadly” in Irish

Irish:
básúil
English:
deadly
Word type:
adjective
Deadlier:
níos básúla
Deadliest:
is básúla
Plural:
básúla
Pronunciation:
“BAW-sool”  /ˈbɑːsuːlʲ/

What does “básúil” mean?

deadly
Able to cause death; fatal or lethal.Also: fatal, lethal, mortal.

Other Irish adjectives for deadly: marfach (deadly)

“Básúil” after a noun

An Irish adjective comes after its noun. Here is básúil after galar (disease, masculine), after bean (woman, feminine) and after a plural.

after a masculine noungalar básúila deadly disease
after a feminine nounbean bhásúila deadly woman
after a plural noungalair bhásúladeadly diseases

séimhiú (the h) the ending

feminine
beanwoman
+
básúildeadly
=
bean bhásúila deadly woman

After a feminine noun the adjective gets a séimhiú, an h after its first letter: bean bhásúil. After a masculine noun it stays as it is: galar básúil.

plural
galairdiseases
+
básúladeadly, plural
=
galair bhásúladeadly diseases

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

Deadlier, deadliest, very deadly

níosmore
+
básúladeadly
=
níos básúladeadlier
ismost
+
básúladeadly
=
is básúladeadliest

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

deadlierníos básúlain the past tense: ní ba bhásúla
deadliestis básúlain the past tense: ba bhásúla
as deadly aschomh básúil leno change after chomh
very deadlyan-bhásúilan- lenites, except d, t and s
too deadlyróbhásúilró- lenites

“Básúil” in a sentence: Irish examples

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

Is galar básúil é an galar sin.
That disease is a deadly disease.
Thóg sé nimh bhásúil de thimpiste.
He took a deadly poison by accident.
Tá nathracha básúla san Astráil.
There are deadly snakes in Australia.
Tá an víreas seo níos básúla ná an ceann eile.
This virus is deadlier than the other one.
Tá an bia sin básúil do mhadraí.
That food is deadly for dogs.

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 básúil (pronounced “BAW-sool”). It comes after the noun: galar básúil, a deadly disease; bean bhásúil, a deadly woman.

How do you say deadlier and deadliest in Irish?

níos básúla is deadlier and is básúla is deadliest. In the past tense they become ní ba bhásúla and ba bhásúla.

Why does básúil become bhásúil?

After a feminine singular noun an adjective is lenited: it gets an h after its first letter. So bean bhásúil (a deadly woman) but galar básúil (a deadly disease), because galar is masculine.

What is the plural of básúil?

With a plural noun básúil becomes básúla: galair bhásúla, mná básúla. After a plural that ends in a slender consonant it is lenited as well.

How do you say very deadly in Irish?

an-bhásúil. Too deadly is róbhásúil, and as deadly as is chomh básúil le.

What is the difference between básúil and marfach?

Both mean deadly or fatal. Marfach is the more common everyday word, while básúil comes from bás, death, and is often used of diseases, wounds and poisons.

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