| a2 |
used to introduce one particular thing or person of a group or kind, but one which is not considered known to the listener. [1/3 definitions] |
| abacus |
a device used for counting or calculating. An abacus has beads or other counters that slide along rods or in grooves. |
| abbreviation |
a shortened form of a word or phrase used in writing. |
| abrasive |
something rough used to wear away or polish a surface. [1/2 definitions] |
| accent |
a mark (' or `). Accents are used to show what parts of a word are to be said with more stress. [1/5 definitions] |
| accessible |
able to be obtained, reached, or used. [1/2 definitions] |
| accustom |
to cause (oneself or another) to become used to something over time. |
| acoustics |
the aspects of a room or space that make sounds easy or difficult to hear (used with a plural verb). |
| acre |
a unit of area equal to 43,560 square feet, used to measure land. The acre is a standard unit of measurement in the United States and the United Kingdom. |
| acrylic |
a kind of plastic used to make yarns, paint, and many other things. |
| A.D. |
A.D. is an abbreviation of the Latin words "anno domini." The abbreviation A.D. is used in dates when people are talking about things in history that happened after Jesus Christ was born. The year that Jesus Christ was born is called "1 A.D." The year after that is called "2 A.D." Jesus Christ is considered both God and man in the religion of Christianity, and he is an important figure in the history of the world. The calendar that most people use nowadays was created by Christians. That's why the year of Christ's birth was chosen as a way to divide older times from newer times. This calendar is not the first or only calendar that people in the world have created, but most people nowadays use this particular calendar. Instead of "A.D.," though, people often use "C.E." nowadays, which stands for "Common Era" or "Christian Era." |
| adapt |
to become used to; adjust. [1/2 definitions] |
| adjust |
to change in order to fit in; get used to. [1/3 definitions] |
| adverb |
a word that describes a verb, adjective, or other adverb. Adverbs are also used to modify a whole sentence. |
| aerobics |
(used with a singular or plural verb) a form of exercise that works the heart and lungs to help the body use oxygen better. Running, swimming, biking, or dance are forms of aerobics. |
| aeronautics |
(used with a singular verb) a science that deals with making and flying aircraft. |
| affix |
to attach or join physically (usually used with "to"). [1/2 definitions] |
| after all |
used to remind the listener of an important fact or to ask the listener to consider this fact. [2 definitions] |
| ah |
a word used to express surprise, joy, pain, understanding, dislike, and other feelings. |
| aha |
a word used to express feelings like surprise, success, discovery, or satisfaction. |
| ahoy |
a word used as a greeting to attract the attention of sailors on a ship. |