| 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. |
| 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. |
| air conditioning |
a system that cools air and takes dust and dampness out of it. Air conditioning is used inside buildings and cars. |