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Reactive in Irish (freasaitheach): Meaning, Forms, Examples

The Irish for reactive is freasaitheach: fear freasaitheach, a reactive man.
Updated October 2026Report a mistake

How to say “reactive” in Irish

Irish:
freasaitheach
English:
reactive
Word type:
adjective
More reactive:
níos freasaithí
Most reactive:
is freasaithí
Plural:
freasaitheacha
Pronunciation:
“FRASS-ih-hukh”  /ˈfʲrʲasˠəhəx/

What does “freasaitheach” mean?

reactive
Describes a substance that readily takes part in a chemical reaction.Also: chemically reactive, reacting.

“Freasaitheach” after a noun

An Irish adjective comes after its noun. Here is freasaitheach after fear (man, masculine), after bean (woman, feminine) and after a plural.

after a masculine nounfear freasaitheacha reactive man
after a feminine nounbean fhreasaitheacha reactive woman
after a plural nounfir fhreasaitheachareactive men

séimhiú (the h) the ending

feminine
beanwoman
+
freasaitheachreactive
=
bean fhreasaitheacha reactive woman

After a feminine noun the adjective gets a séimhiú, an h after its first letter: bean fhreasaitheach. After a masculine noun it stays as it is: fear freasaitheach.

plural
firmen
+
freasaitheachareactive, plural
=
fir fhreasaitheachareactive men

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

More reactive, most reactive, very reactive

níosmore
+
freasaithíreactive
=
níos freasaithímore reactive
ismost
+
freasaithíreactive
=
is freasaithímost reactive

Tá potaisiam níos freasaithí ná sóidiam. Potassium is more reactive than sodium.

more reactiveníos freasaithíin the past tense: ní ba fhreasaithí
most reactiveis freasaithíin the past tense: ba fhreasaithí
as reactive aschomh freasaitheach leno change after chomh
very reactivean-fhreasaitheachan- lenites, except d, t and s
too reactiverófhreasaitheachró- lenites

“Freasaitheach” in a sentence: Irish examples

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

Is miotal freasaitheach é an sóidiam.
Sodium is a reactive metal.
Coinnigh an tsubstaint fhreasaitheach sin i bhfad ón uisce.
Keep that reactive substance well away from water.
Stóráiltear miotail fhreasaitheacha faoi ola.
Reactive metals are stored under oil.
Tá potaisiam níos freasaithí ná sóidiam.
Potassium is more reactive than sodium.
Tá an t-ór an-bheagán freasaitheach.
Gold is very slightly reactive.

Other adjectives in Irish

More everyday Irish adjectives to learn next.

Reactive in Irish: frequently asked questions

What is the Irish for reactive?

The Irish for reactive is freasaitheach (pronounced “FRASS-ih-hukh”). It comes after the noun: fear freasaitheach, a reactive man; bean fhreasaitheach, a reactive woman.

How do you say more reactive and most reactive in Irish?

níos freasaithí is more reactive and is freasaithí is most reactive. In the past tense they become ní ba fhreasaithí and ba fhreasaithí.

Why does freasaitheach become fhreasaitheach?

After a feminine singular noun an adjective is lenited: it gets an h after its first letter. So bean fhreasaitheach (a reactive woman) but fear freasaitheach (a reactive man), because fear is masculine.

What is the plural of freasaitheach?

With a plural noun freasaitheach becomes freasaitheacha: fir fhreasaitheacha, mná freasaitheacha. After a plural that ends in a slender consonant it is lenited as well.

How do you say very reactive in Irish?

an-fhreasaitheach. Too reactive is rófhreasaitheach, and as reactive as is chomh freasaitheach le.

What is the noun related to 'freasaitheach'?

The related chemistry nouns are 'imoibriú' or 'freasaíocht', meaning reaction or reactivity.

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