| Dactyliology | study of rings (see list of branches of science) |
| Dactylography | study of fingerprints (see list of branches of science) |
| Dactylology | study of sign language (see list of branches of science) |
| Daemonophobia | fear of demons (see list of phobias) |
| Decidophobia | fear of making decisions (see list of phobias) |
| Defecaloesiophobia | fear of painful bowels movements (see list of phobias) |
| Deipnophobia | fear of dining or dinner conversations (see list of phobias) |
| Deltiology | collection of postcards (see list of hobbies) |
| Dementophobia | fear of insanity (see list of phobias) |
| Demography | study of population (see list of branches of science) |
| Demology | study of human behaviour (see list of branches of science) |
| Demonophobia | fear of demons (see list of phobias) |
| Demophobia | fear of crowds (see list of phobias) |
| Dendrochronology | study of tree rings (see list of branches of science) |
| Dendrology | study of trees (see list of branches of science) |
| Dendrophobia | fear of trees (see list of phobias) |
| Dentophobia | fear of dentists (see list of phobias) |
| Deontology | study of moral obligation (see list of branches of science) |
| Dermatoglyphics | study of skin patterns and fingerprints (see list of branches of science) |
| Dermatology | study of skin (see list of branches of science) |
| Dermatopathophobia | fear of skin disease (see list of phobias) |
| Dermatophobia | fear of skin disease or skin lesions (see list of phobias) |
| Dermatosiophobia | fear of skin disease (see list of phobias) |
| Desmology | study of ligaments (see list of branches of science) |
| Dextrophobia | fear of objects at the right side of the body (see list of phobias) |
| Diabetophobia | fear of diabetes (see list of phobias) |
| Diabology | study of devils (see list of branches of science) |
| Dialectology | study of dialects (see list of branches of science) |
| Didaskaleinophobia | fear of going to school (see list of phobias) |
| Dietetics | study of prevention of health conditions and diseases through human nutrition and regulation of diet (see list of branches of science) |
| Dikephobia | fear of justice (see list of phobias) |
| Dinophobia | fear of dizziness or whirlpools (see list of phobias) |
| Dioptrics | study of light refraction (see list of branches of science) |
| Diplomatics | study of deciphering ancient writings and texts (see list of branches of science) |
| Diplomatology | study of diplomats (see list of branches of science) |
| Diplophobia | fear of double vision (see list of phobias) |
| Dipsophobia | fear of drinking (see list of phobias) |
| Dishabiliophobia | fear of undressing in front of someone (see list of phobias) |
| Disposophobia | fear of throwing stuff out or hoarding (see list of phobias) |
| Docimology | study of assaying (see list of branches of science) |
| Domatophobia | fear of houses or being in a house (see list of phobias) |
| Doraphobia | fear of fur or hides or skins of animals (see list of phobias) |
| Dosiology | study of doses (see list of branches of science) |
| Doxophobia | fear of expressing opinions or of receiving praise (see list of phobias) |
| Dromophobia | fear of crossing streets (see list of phobias) |
| Dutchphobia | fear of the Dutch (see list of phobias) |
| Dynamics | study of forces and their effects on motion (see list of branches of science) |
| Dysgenics | study of racial degeneration (see list of branches of science) |
| Dysmorphophobia | fear of deformity (see list of phobias) |
| Dystychiphobia | fear of accidents (see list of phobias) |
| |
|
|
|
