Ology Suffix Words starting with D
| Dactyliology | the study and making of finger rings |
| Dactylology | the study of sign language |
| Deltiology | the study and the collecting of picture postcards |
| Demology | the study of human behaviour |
| Demonology | the study of demons |
| Dendrochronology | the study of the age of trees and the records in their rings |
| Dendrology | the study of trees |
| Deontology | the ethical study of duties, obligations, and rights. |
| Dermatology | the field of medicine that deals with the skin |
| Dermatopathology | the study of cutaneous diseases at a microscopic level |
| Desmology | the study of ligaments |
| Diabology | the study of devils |
| Dialectology | the study of dialects |
| Dinosaurology | the study of dinosaurs |
| Diplomatology | the study of diplomats |
| Dipterology | the study of flies |
| Docimology | the art of assaying(metals) |
| Dosiology | the study of doses |