1.                  debilitating (adj.), debilitation (n.), debilitate (v.)  يضعف – incapacitating, weakening

AIDS is a debilitating disease.

2.                  defective (adj.), defect (n.) فيه خلل أو عيب – faulty, imperfect, flawed

A defective heart valve can lead to health problems.

3.                  defend (v.), defense (n.) يدافع عن – to say or to write something to support somebody or something

Although everyone said Faisal was wrong, he defended his answer to the question.

4.                  deficiency (n.) نقص – lack of

He suffered from a deficiency of vitamin A.

5.                  definite (adj.) واضح – clear; easy to see or notice

There was a definite change in the liquid after the catalyst was added.

6.                  degenerative (adj.), degenerate (v.), degeneration (n.) مخل – worsening (without hope of improvement), deteriorating

Huntington’s disease is a degenerative disease.

7.                  depression (n.), depress (v.), depressed (adj.) اكتئاب – dejection, gloom

He suffered from depression because of the death of his child.

8.                  deranged (adj.)  مشوش– abnormal in appearance

The cells had become deranged and no longer resembled the parent cell.

9.                  derive (v.) يشتق – to come from

The main ingredient in the painkiller is derived from a common plant.

10.              detect (v.), detection (n.) يكتشف – identify, discover

Researchers have not detected the cause of autism.

11.              devastate (v.), devastation (n.), devastated (adj.)  مهجور – crush, desolate

The bad news devastated his mother.

12.              dimension (n.) بعد – measurement (e.g., length, height)

What are the dimensions of the new building?

13.              discover (v.), discovery (n.)   يكتشف– learn, determine, detect

Scientists have discovered that a mutant gene causes the disease.

14.              disparity (n.)   اختلاف – difference

Most new cells failed to develop; however, new cells in the hippocampus did mature. This disparity may be because they are needed there.

15.              dissipate (v.) يشتت – scatter; make disappear; disintegrate; dissolve

Drinking a lot of water dissipates the toxin.

16.              dissolve (v.) يذوب – to make something solid become part of a liquid by putting it in a liquid

Sugar dissolves in water.

17.              distorted (v.), distortion (n.) distorted (adj.) يشوه – change so that something appears unnatural

The chemical distorted the natural shape of the object.

18.              distribution (n.), distribute (v.) توزيع  – location, dispersal

The map shows the distribution of AIDS cases throughout the world.

19.              divide يقسم (v.), division (n.), divided (adj.) – separate, split

They divided the work among themselves.

20.              dizzy (adj.), dizzily (adv.), dizziness (n.) مصاب بدوار

The heat made me dizzy.

21.              dome (n.), domed (adj.) قبة – a shape like a ball cut in half

The object was shaped like a dome.

22.              donor (n.), donate (v.) مانح – giver, supplier

I hope there will be a kidney donor.

23.              droplet (n.) قطرة صغيرة جداً – drop, bead, globule, drip

The technician placed a droplet of blood on the glass slide.

24.              early (adj.) مبكرا – initial

Early signs of measles are fever and runny nose.

25.              effect (n.) أثر – a change that is caused by something

The effect of the diet was weight loss.

26.              embed (v.)   يغرز به بإحكام– to fix something deeply and firmly in something else

A piece of glass was embedded in the wound.

27.              enable يمكن - يخول (v.) – allow, facilitate, permit, make possible

Studying the vocabulary words enables students to pass the vocabulary test.

28.              enlarge (v.), enlargement (n.), enlarged (adj.) يكبر - make bigger, increase, expand

I asked the man to enlarge the photograph to a bigger size.

29.              entire (adj.), entirely (adv.) كامل – whole, complete, total

I completed the entire task in less than one hour.

30.              equipment (n.) معدات (n.) – (This noun is always singular.) tools, utensils, apparatus

The equipment included a Bunsen burner, tube, and beaker.

31.              eradicate (v.), eradication (n.) يستأصل – eliminate, get rid of, wipe out

Smallpox has almost been eradicated.

32.              essential (adj.) أساسي – vital, crucial, critical

Treatment is essential if a patient is to recover from bubonic plague.

33.              evaporate (v.), evaporation (n.), evaporated (adj.) يتبخر – if a liquid evaporates or if something evaporates, it changes into steam; if a feeling evaporates, it slowly disappears

The water evaporated into hot steam.

Hope of reaching an agreement is evaporating.

34.              exaggerated (adj.)  متضخم  – larger than normal, overly large

The hematoma was exaggerated in size.

35.              execute (v.)   ينجز– carry out, perform

The vocal cords execute a series of well-coordinated movements during swallowing.

36.              exhibit (v.)   يبدو– show, display, demonstrate

He exhibited signs of paranoia.

37.              expansive (adj.), expanse (n.) متمدد – vast, extensive, sizeable, large

The room was expansive.

38.              extraordinary (adj.) غير مألوف – unexpected, unusual

Winning $1 million was extraordinary.

39.              extraordinary (adj.) غريب – strange, odd

It was extraordinary that he didn’t know his own brother’s name.

40.              extraordinary (adj.)  استثنائي– special, exceptional, remarkable

The discovery of the new star in the solar system was extraordinary.

41.              facilitate (v.)  يمكن– enable

A gastroscope is an instrument that enables exploration of the upper gastric tract.

42.              fatigue (n.) إرهاق – exhaustion, weariness

Because of fatigue, the woman fell asleep immediately after she went to bed.

43.              feature (n.)  ميزه – characteristic, trait, aspect, symptom

One feature of the disease is trembling.

44.              fidget (v.), fidgety (adj.)  متململ– move around restlessly

The little boy fidgeted in his chair.

45.              filtered (adj.), filtration (n.), filter (v.) يصفي

The filtered water did not contain foreign matter.

46.              flake (n) قشارة - a very small flat thin piece that breaks away easily or has been broken away from something else

The maid used soap flakes to wash the sweater.