Ruis (letter)
| Ogham letters ᚛ᚑᚌᚐᚋᚁᚂᚃᚓᚇᚐᚅ᚜ | |||||
| Aicme Beithe ᚛ᚐᚔᚉᚋᚓᚁᚂᚃᚄᚅ᚜ |
Aicme Muine ᚛ᚐᚔᚉᚋᚓᚋᚌᚍᚎᚏ᚜ | ||||
| ᚁ | [b] | Beith | ᚋ | [m] | Muin |
| ᚂ | [l] | Luis | ᚌ | [ɡ] | Gort |
| ᚃ | [w] | Fearn | ᚍ | [ɡʷ] | nGéadal |
| ᚄ | [s] | Sail | ᚎ | [st], [ts], [sw] | Straif |
| ᚅ | [n] | Nion | ᚏ | [r] | Ruis |
| Aicme hÚatha ᚛ᚐᚔᚉᚋᚓᚆᚇᚈᚉᚊ᚜ |
Aicme Ailme ᚛ᚐᚔᚉᚋᚓᚐᚑᚒᚓᚔ᚜ | ||||
| ᚆ | [j] | Uath | ᚐ | [a] | Ailm |
| ᚇ | [d] | Dair | ᚑ | [o] | Onn |
| ᚈ | [t] | Tinne | ᚒ | [u] | Úr |
| ᚉ | [k] | Coll | ᚓ | [e] | Eadhadh |
| ᚊ | [kʷ] | Ceirt | ᚔ | [i] | Iodhadh |
| Forfeda ᚛ᚃᚑᚏᚃᚓᚇᚐ᚜ | |||||
| ᚕ | [ea], [k], [x], [eo] | Éabhadh | |||
| ᚖ | [oi] | Ór | |||
| ᚗ | [ui] | Uilleann | |||
| ᚘ | [ia] | Ifín | |||
| ᚙ | [x], [ai] | Eamhancholl | |||
| ᚚ | [p] | Peith | |||
Ruis (ᚏ) is the fifteenth letter of the Ogham alphabet, derived from ruise "red" or "reddening". The kennings refer to the reddening of the face caused by intense emotion, and medieval glossators also refer to the practice of reddening the cheeks with the juice of plants. Its Proto-Indo-European root was *h₁reudʰ- 'red'. Its phonetic value is [r].