| Term | Definition | Contributor | Modified |
|---|---|---|---|
| Walloon poetry | No definition provided | Christopher Rauch | 2023.12.01 |
| Walloons | No definition provided | Christopher Rauch | 2023.12.01 |
| Wall-painting | No definition provided | Christopher Rauch | 2023.12.01 |
| Wall-paper | No definition provided | Christopher Rauch | 2023.12.01 |
| Walls | No definition provided | Christopher Rauch | 2023.12.01 |
| Wall street | No definition provided | Christopher Rauch | 2023.12.01 |
| Walnut | No definition provided | Christopher Rauch | 2023.12.01 |
| Walnut span-worm | No definition provided | Christopher Rauch | 2023.12.01 |
| Walpurgite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Walraven photometry | A photometric system with five wavelength ranges that does not use filters. Instead it uses prisms and lenses (spectroscopy) to select the bands simultaneously. The wavelengths and the bandwidths are: W, 3250 and 140 Å; U, 3630 and 240 Å; L, 3840 and 230 Å; B, 4320 and 450 Å; and V, 5470 and 720 Å. The Walraven photometer was unique in design and remained literally unique as copies were never built. In addition, during its whole life the photometer was mounted permanently on the same telescope that had been built specifically for this instrument, the 91 cm 'Lightcollector' reflector, which started in 1958 at the Leiden Southern Station in Broederstroom, South-Africa. After 20 years in South-Africa the telescope and photometer were moved to the European Southern Observatory La Silla observatory in Chile. The photometric observations were resumed in March 1979 and continued for another 12 years until the decommissioning of the photometer in 1991. | Ryan McGranaghan | 2023.04.16 |
| Walrus | No definition provided | Christopher Rauch | 2023.12.01 |
| Walschaert valve-gear | No definition provided | Christopher Rauch | 2023.12.01 |
| Walstromite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| walthers law | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Walthierite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Waltz | No definition provided | Christopher Rauch | 2023.12.01 |
| Wamesit Indians | No definition provided | Christopher Rauch | 2023.12.01 |
| Wampanoag Indians | No definition provided | Christopher Rauch | 2023.12.01 |
| Wampanoag Indians--Missions | No definition provided | Christopher Rauch | 2023.12.01 |
| Wampum | No definition provided | Christopher Rauch | 2023.12.01 |