dacry- or dacryo- [from Greek dacron tear] (1) tears (dacryagogue); (2) lacrimal sac (dacryelcosis).

dacryocyst- or dacryocysto- [dacryo + cyst] Denotes the lacrimal sac (dacryocystitis).

dactyl- or dactylo- [from Greek dactylos finger] Finger (dactyloid).

de- [Latin de down from, away from, from, off] (1) from (decubital); (2) do the opposite (decomposer); (3) remove, reduce (dehydrate, deoxy-).

deca- [from Greek deka ten] Ten (decaliter).

decem- [from Latin decem ten] Ten (December).

deci- [from Greek deka ten] One tenth (decimorgan).

demi- [from Latin dimidiare to halve] Half (demilune).

dendr- or dendro- [from Greek dendron tree] Denotes a tree or treelike thing (Dendrobatidae, dendrochronology, dendrology).

dent- or denti- or dento- [from Latin dens, dentis tooth; tooth-like thing] Tooth (dentary, dentulous).

deoxy- [de + oxy-] Containing less oxygen (deoxyribonucleic acid).

der- or dero- [from Greek dere neck] Having a neck or throat (or a disease thereof) of the type indicated by the stem or suffix (Derotremata).

derm- or derma- or dermo- or dermat- or dermato- [from Greek derma skin] Denotes skin (dermal).

desm- or desmo- [from Greek dein to bind] A bond, tie, ligature (desmosome).

dextro- [from Latin dexter, dextra right, on the right hand] To the right (dextrocardia, dextrorotatory, dextroversion).

di- or dia- or dis- [from Greek dis double, twice] double, twice, two (diploid, diotic).

di- or dia- [from Greek dia through, by] (1) through, between (diarrhea, diatom); (2) asunder, apart (diastasis, diastole); (3) completely (diagnosis).

di- or dif- or dis- [from Latin de down from, away from, from, off] Apart, separation, taking apart (dissect).

didym- or didymo- [from Greek didymos twin, testis] (1) testis (didymitis); (2) twin (didymus).

dipl- or dipla- or diplo- [from Greek diploos twofold, double] Double (diploblastic, diploid, diplophase, diplotene).

dis- [from Latin de down from, away from, from, off] (1) negative, not, opposite (disequilibrium); (2) free of, undo (disinfect).

dodec- or dodeca- [from Greek dyodeka twelve] Twelve (dodecandrous).

dors- or dorsi- or dorso- [from Latin dorsum back] Pertaining to the back, at the back, in back (dorsolateral).

dry- or dryo- [from Greek drys tree, oak] Tree, oak (dryopithecine).

dy- or dyo- [from Greek dyo two] Two, a pair, in pairs (dyad).

dynam- or dynamo- [from Greek dynamis power] Denotes power (dynamometer).

dys- [from Greek dys- bad, abnormal, difficult, defective] (1) abnormal (dysplasia); (2) impaired (dysneuria); (3) difficult (dyspnea); (4) bad (dyspepsia, dysentery).