déhéidreach

Irish

Etymology

From dé- (“di-”) +‎ -héidreach (“-hedral”).

Adjective

déhéidreach (genitive singular masculine déhéidrigh, genitive singular feminine déhéidrí, plural déhéidreacha, not comparable)

1. (mathematics, aeronautics) dihedral

Declension

Declension of déhéidreach

Positive	singular		plural
	masculine	feminine	strong noun	weak noun
nominative	déhéidreach	dhéhéidreach	déhéidreacha; dhéhéidreacha2
vocative	dhéhéidrigh		déhéidreacha
genitive		déhéidrí	déhéidreacha	déhéidreach
dative	déhéidreach; dhéhéidreach1	dhéhéidreach; dhéhéidrigh (archaic)	déhéidreacha; dhéhéidreacha2
Comparative	níos déhéidrí
Superlative	is déhéidrí

¹ When the preceding noun is lenited and governed by the definite article.
² When the preceding noun ends in a slender consonant.

Related terms

• déhéadrán m (“dihedron”)

Mutation

Mutated forms of déhéidreach

radical	lenition	eclipsis
déhéidreach	dhéhéidreach	ndéhéidreach

Note: Certain mutated forms of some words can never occur in standard Modern Irish.
All possible mutated forms are displayed for convenience.

Further reading

• Ó Dónaill, Niall (1977) “déhéidreach”, in Foclóir Gaeilge–Béarla, Dublin: An Gúm, →ISBN
• de Bhaldraithe, Tomás (1959) “déhéidreach”, in English-Irish Dictionary, An Gúm
• “déhéidreach”, in New English-Irish Dictionary, Foras na Gaeilge, 2013–2025