From Old Irish *riug, from Proto-Celtic *rigus, from Proto-Indo-European *h₃réǵ-u-s ~ *h₃r̥ǵ-éw-s (“straight”), from Proto-Indo-European *h₃reǵ-. Sanskrit ऋजुः ~ ऋजोः (ṛjúḥ ~ ṛjóḥ, “straight”) is a precise cognate, both having generalised zero grade in the root. Ancient Greek ὀρεκτός (orektós), Latin rēctus, and English right are also related.
Because u-stem adjectives are rare in Old Irish, it is unlikely to have been borrowed from Latin dīrectus, but the addition of the intensive prefix di- could have been influenced by the Latin term of the same meaning.[1]
díriuch (comparative dírgu)
| u-stem | |||
|---|---|---|---|
| Singular | Masculine | Feminine | Neuter |
| Nominative | díriuch | díriuch | díriuch |
| Vocative | díriuch | ||
| Accusative | díriuch | dírig | |
| Genitive | dírig | dírgae | dírig |
| Dative | díriuch | dírig | díriuch |
| Plural | Masculine | Feminine/neuter | |
| Nominative | dírgai | dírgai | |
| Vocative | dírgai | ||
| Accusative | dírgai | ||
| Genitive | * | ||
| Dative | dírgaib | ||
| Notes | *not attested in Old Irish; same as nominative singular masculine in Middle Irish | ||
| radical | lenition | nasalization |
|---|---|---|
| díriuch | díriuch pronounced with /ð(ʲ)-/ |
ndíriuch |
Note: Certain mutated forms of some words can never occur in Old Irish.
All possible mutated forms are displayed for convenience.