Miscellaneous
- The letter ð is sometimes used in mathematics and engineering textbooks as a symbol for a spin-weighted partial derivative. This operator gives rise to spin-weighted spherical harmonics.
- The modern Greek letter delta (Δ, δ) has, in general, the same phonetic value, and ð is the only Latin alphabet letter faithfully representing delta's phonetic value. (In Ancient Greek, delta represented a d sound.)
- The symbol is mentioned in the Rush song "By-Tor and the Snow Dog" in the first verse:
Prince By-Tor takes the cavern to the North light,
The sign of Eth is rising in the air.
Read more about this topic: Eth