accuis

• accuiss, acuis
• accais, acais (later manuscripts)

• IPA^(key): [ˈakusʲ]

Borrowed from Late Latin *accāsiō, from Latin occāsiō, whence also Middle Welsh achaws (modern Welsh achos).

accuis f

1. cause, occasion, reason

Feminine n-stem
	Singular	Dual	Plural
Nominative	accuis	aicsinL	aicsin
Vocative	accuis	aicsinL	aicsenaH
Accusative	aicsinN	aicsinL	aicsenaH
Genitive	aicsen	aicsenL	aicsenN
Dative	aicsinL, accuisL	aicsenaib	aicsenaib
Initial mutations of a following adjective: H = triggers aspiration L = triggers lenition N = triggers nasalization

• fochonn

• acis

From ad- + Proto-Celtic *kassis (“hatred”).^[1]

accuis f (nominative plural acsi)

1. offence, hatred

Feminine i-stem
	Singular	Dual	Plural
Nominative	accuis	accuisL	aicsiH
Vocative	accuis	accuisL	aicsiH
Accusative	accuisN	accuisL	aicsiH
Genitive	aicseoH, aicseaH	aicseoH, aicseaH	aicseN
Dative	accuisL	aicsib	aicsib
Initial mutations of a following adjective: H = triggers aspiration L = triggers lenition N = triggers nasalization

• Middle Irish: accais, acaiss, acuis (“cause; offense; hatred; venom”)
  • Irish: aicis, acais (“venom, spite”)

Old Irish mutation
Radical	Lenition	Nasalization
accuis (pronounced with /h/ in h-prothesis environments)	unchanged	n-accuis
Note: Some of these forms may be hypothetical. Not every possible mutated form of every word actually occurs.

• Gregory Toner, Sharon Arbuthnot, Máire Ní Mhaonaigh, Marie-Luise Theuerkauf, Dagmar Wodtko, editors (2019), “accais”, in eDIL: Electronic Dictionary of the Irish Language