| Word | Definition |
| Deciduous | falling off or shed seasonally; Ephemeral |
| Decipher | to decode |
| Declivity | downward slope |
| Decollete | wearing a strapless or low-necked dress |
| Decomposition | decay |
| Decorum | propriety; orderliness and good taste in manners |
| Decoy | to lure; to bait |
| Decrepitude | state of collapse caused by illness or old age |
| Decry | to express strong disapproval of; disparage |
| Deducible | derived by reasoning |
| Deface | to mar; to disfigure |
| Defame | to harm the reputation of by slander |
| Default | failure to act: neglect; forfeit |
| Defeatist | resigned to defeat; accepting defeat as a natural outcome |
| Defection | desertion |
| Defer | to delay till later; to exempt temporarily |
| Defer | to give in respectfully; to submit |
| Deference | courteous regard for another's wish |
| Defiance | Refusal to yield; resistance |
| Defile | to pollute; to profane |
| Definitive | most reliable or complete |
| Deflect | to turn aside |
| Defoliate | to destroy leaves |
| Defray | to provide for the payment of |
| Defrock | to strip a priest or minister of church authority |
| Deft | neat; skillful |
| Defunct | dead; no longer in use or existence |
| Degenerate | to become worse; to deteriorate |
| Degradation | humiliation; debasement; degeneration |
| Dehydrate | to remove water from; to dry out |
| Deify | to turn into a god; to idolize |
| Deign | to condescend; to stoop |
| Delete | to erase; to strike out |
| Deleterious | harmful |
| Deliberate | to consider; to ponder |
| Delineate | to portray; to depict; to sketch |
| Delirium | mental disorder marked by confusion |
| Delta | flat plain of mud or sand between branches of a river |
| Delude | to deceive |
| Deluge | flood; rush |
| Delusion | false belief; hallucination |
| Delusive | deceptive; raising vain hopes |
| Delve | to dig; to investigate; to examine a subject in detail |
| Demagogue | person who appeals to people's prejudice; false leader |
| Demean | to degrade; to humiliate |
| Demeanor | behavior; bearing |
| Demented | insane |
| Demise | death |
| Demographic | segment of population identified |
| Demolition | destruction |
| Demoniac | fiendish |
| Demotic | pertaining to the people |
| Demur | object; hesitate |
| Demure | modest;reserved; serious; coy |
| Denigrate | to defame; to belittle |
| Denizen | inhabitant or resident; regular visitor |
| Denotation | meaning; distinguishing by name |
| Denouement | outcome; final development of the plot of a play |
| Denounce | to condemn; to criticize |
| Depict | to portray |
| Delete | to reduce; to exhaust |
| Deplore | to regret or feel grief; to condemn |
| Deploy | to spread out; to extend |
| Depose | to dethrone; to remove from office |
| Deposition | testimony under oath |
| Depravity | a corrupt act or practice |
| Deprecate | to express disapproval of; to protest against |
| Depreciate | to lessen in value |
| Depredation | ravaging |
| Deranged | insane |
| Derelict | abandoned; negligent |
| Deride | to ridicule; to make fun of |
| Derivative | unoriginal; obtained from another source |
| Dermatologist | one who studies the skin and its diseases |
