The Cirth (; plural of certh , in Sindarin meaning runes) are a semi- artificial script, with letters shaped on those of actual runic alphabets, invented by J.R.R. Tolkien for the constructed languages he devised and used in his works. Cirth is written with a capital letter when referring to the writing system; the runes themselves can be called cirth.
In the fictional history of Middle-earth, the original Certhas Daeron was created by the elf Daeron, and was later expanded into what was known as the Angerthas Daeron. Although the Cirth were later largely replaced by the Tengwar, they were adopted by Dwarves to write down their Khuzdul language (Angerthas Moria and Angerthas Erebor) because their straight lines were better suited to carving than the curved strokes of the Tengwar. Cirth was also adapted, in its oldest and simplest form, by various peoples as Men and even Orcs.