| Term | Definition | Contributor | Modified |
|---|---|---|---|
| Young stellar objects | Any star that has evolved past the protostar stage, but has not yet arrived on the main sequence. There is a variety of YSOs depending on their age, mass, and environment, including Herbig stars, T Ta uri stars, and, in general, compact infrared sources embedded in molecular clouds. | Ryan McGranaghan | 2023.04.16 |
| Young-Turkish party | No definition provided | Christopher Rauch | 2023.12.01 |
| Young women | No definition provided | Christopher Rauch | 2023.12.01 |
| Young women's Christian associations | No definition provided | Christopher Rauch | 2023.12.01 |
| youth | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Youth | No definition provided | Christopher Rauch | 2023.12.01 |
| ypresian | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrialite (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrian Datolite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrium | No definition provided | Christopher Rauch | 2023.12.01 |
| Yttrium earths | No definition provided | Christopher Rauch | 2023.12.01 |
| Yttrobetafite (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttroceberite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttroceberysite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrocerite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrocolumbite (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrocrasite (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrofluorite | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttropyrochlore (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |
| Yttrotantalite (Y) | No definition provided | Ryan McGranaghan | 2023.04.16 |