HeyRua Get the app

Lenition in Irish (Séimhiú): Meaning, Pronunciation, Usage

‘séimhiú’ also means: mellowing

The Irish for lenition is séimhiú, a masculine noun. Ag séimhiú is leniting, from the verb séimhigh.
Updated October 2026Report a mistake

How to say “lenition” in Irish

Irish:
séimhiú
English:
lenition, mellowing
Word type:
noun (verbal noun)
Verbal noun of:
séimhigh, to lenite (ag séimhiú, leniting)
Gender:
masculine
Pronunciation:
“SHAY-voo”  /ˈʃeːvʲuː/
Various forms
Genitive singular:
séimhithe, an tséimhithe (e.g. rialacha an tséimhithe, the rules of lenition)

What does “séimhiú” mean?

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

lenition
The grammatical mutation in Irish that softens an initial consonant, usually shown in writing by adding h after it.Also: aspiration, softening, initial mutation.
1 other meaning: mellowing
2mellowing
The act of softening or mellowing something; the verbal noun of the verb séimhigh.Also: softening, attenuation.

“Séimhiú” as a verbal noun

After ag, séimhiú means leniting: it is the verbal noun of the verb séimhigh (to lenite). A noun that follows it goes into the genitive.

agat
+
séimhiúverbal noun
=
ag séimhiúleniting

“Séimhiú” with the article

Here is séimhiú after the article (an t-alt).

an séimhiú
the lenition
No change after an

“Séimhiú” in a sentence: Irish examples

Common Irish sentences using séimhiú, the Irish word for lenition.

Cuirtear séimhiú ar an ainmfhocal tar éis mo.
The noun is lenited after mo.
Ní thuigim an séimhiú fós.
I still don't understand lenition.
Tá séimhiú ar an mbriathar san aimsir chaite.
The verb is lenited in the past tense.
Rinne mé dearmad ar an séimhiú arís.
I forgot the lenition again.
Mhínigh an múinteoir rialacha an tséimhithe dúinn.
The teacher explained the rules of lenition to us.
Ní bhíonn séimhiú ar l, n ná r i scríbhinn.
L, n and r are not lenited in writing.
Tá botún séimhithe i do chuid oibre.
There is a lenition mistake in your work.

Other nouns in Irish

More everyday Irish nouns to learn next.

Lenition in Irish: frequently asked questions

What is the Irish for lenition?

The Irish for lenition is séimhiú (pronounced “SHAY-voo”). It’s a masculine noun. Depending on context it can also mean mellowing.

How do you pronounce séimhiú in Irish?

Séimhiú is said like “SHAY-voo” (IPA /ˈʃeːvʲuː/).

Does séimhiú have a plural?

No plural form is given for séimhiú in the standard. Many abstract and mass nouns in Irish have no plural.

Does séimhiú have more than one meaning?

Yes. Séimhiú can mean lenition or mellowing, depending on context; the first is the most common.

Why does séimhiú change to shéimhiú?

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

What is the difference between séimhiú and urú?

Séimhiú (lenition) adds h after a consonant, as in mo bhád, while urú (eclipsis) puts a letter before it, as in ár mbád.

How do I say a word is lenited?

You say tá séimhiú air, or use the verb: séimhítear an consan.

Learn Irish by
actually speaking it

Learn everyday Irish words like séimhiú through guided conversation with Rua.

7-day free trial. Cancel anytime.

The HeyRua app home screen