1:
abbreviation 
shortening something by omitting parts of it
2:
abnormal 
unusual; not typical; not normal
3:
abort 
stop; terminate before completion; terminate a pregnancy
4:
abrasion 
scratch; friction
5:
abrasive 
rubbing away; tending to grind down
6:
absence 
state of being absent; state of being away
7:
absolutely 
utterly; definitely
8:
abstract 
theoretical; not concrete; not applied or practical; difficult to understand
9:
abstract 
summary; statement summarizing the important points of a text
10:
accidental 
unexpected; unforeseen
11:
accompany 
travel with; be associated with
12:
accomplished 
skilled; experienced; having many social graces; polished or refined
13:
accounting 
system that provides quantitative information about finances
14:
acid 
sour; water-soluble compounds having a sour taste; quality of being sarcastic, bitter, or scornful
15:
acidic 
tasting sour like acid; being or containing an acid
16:
actual 
true; real; being, existing, or acting at the present moment; current
17:
actually 
truly; really; in fact
18:
acupuncture 
treatment of pain or disease by inserting the tips of needles at specific points on the skin
19:
adequate 
sufficient; enough to meet a purpose
20:
adhere 
stick fast; stick to firmly; be compatible or in accordance with
21:
adhesive 
sticky; glutinous; tending to persist
22:
adjunct 
something added on or attached generally nonessential or inferior
23:
admit 
permit to enter; receive; provide the right or a means of entrance to
24:
adventure 
something happens without design; chance; hazard; risk; danger
25:
adventurous 
valiant; venturesome; inclined or willing to incur hazard or engage in adventures
26:
adversity 
state of misfortune, hardship, or affliction; misfortune
27:
advocate 
speak, plead, or argue in favour of; plead for; push for something
28:
aerodynamics 
study of how objects move through the air or water
29:
affected 
speaking or behaving in artificial way; emotionally stirred or moved; infected or attacked
30:
affective 
sentimental; emotional; emotionally charged
31:
aggravate 
worsen; make worse or more troublesome
32:
aggregation 
several things grouped together or considered as a whole
33:
ailment 
sickness; illness; affliction
34:
aircraft 
vehicle that can fly, such as an airplane, helicopter, balloon
35:
alert 
warning serves; alarm; condition of heightened watchfulness or preparation for action
36:
alike 
similar; in the same manner or to the same degree
37:
allegation 
suggestion without proof that someone has done something wrong
38:
alliteration 
repetition of beginning sound in poetry
39:
alone 
solitary; by oneself
40:
alteration 
passage from one form or state to another; change