- Projection from the surface, typically of a mucous membrane.
- Elongated projection of the dermis into an epidermal space.
Source:
PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 820 (https://doi.org/10.1515/pac-2015-1202)