| 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. |
| alga |
singular form of "algae." |
| algae |
organisms that live mainly in the water and make their food through photosynthesis. Algae are different from plants in that they have no true leaves, roots, or stems. Seaweeds are algae. "Algae" is a plural noun; the singular form is "alga." |
| amends |
(used with a singular or plural verb) something given or paid to make up for a wrong done to a person or group. |
| bacterium |
singular form of "bacteria." Bacteria are tiny living things made up of one cell each. Bacteria live in most living things and in all parts of the earth. Most bacteria are useful to people, but some are harmful because they can cause disease. |
| bellows |
(used with a singular or plural verb) a bag that can be expanded to draw air in and squeezed to force air out. Bellows are used to blow air on a fire or produce sound on a musical instrument. |
| blues |
(used with a singular or plural verb) a style of sad-sounding music with roots in African American folk music. Jazz and rock music developed from the blues. [1/2 definitions] |
| checkers |
(plural but used with a singular verb) a game played by two people. Each player has twelve pieces to move over a board divided into sixty-four squares of two alternating colors. |
| confetti |
(used with a singular verb) small pieces of colored paper thrown into the air during parades, parties, and other festivities. |
| custom |
(plural but used with a singular verb) the process in which official people inspect goods and question travelers about what things they are bringing into a country, or the place where this is done. [2/4 definitions] |
| daddy-longlegs |
(used with a singular or plural verb) a small animal that resembles a spider. Daddy-longlegs are arachnids and have a small, rounded body with eight very long, thin legs. |
| dart |
(plural, but used with a singular verb) a game in which these objects are thrown at a target. [1/4 definitions] |
| data |
facts, figures, or other pieces of information that can be used to learn about something. The word "data" is the plural form of "datum," but is often used with a singular verb. |
| die2 |
singular of "dice." |
| domino1 |
(plural, but used with a singular verb) a game played with such pieces. [1/2 definitions] |
| downstairs |
(used with a singular verb) the lower floor or floors. [1/3 definitions] |
| economics |
(used with a singular verb) the study of how goods and services are produced and distributed. |
| electronics |
(used with a singular verb) the science that is concerned with the flow of electrons and their uses. |
| genetics |
(used with a singular verb) the science that studies how characteristics are passed on from parent to offspring. Genetics is concerned with the influence of genes on the appearance, development, and evolution of plants and animals. |
| graphics |
(used with a singular or plural verb) the process of making drawings, charts, and other images on a computer screen. [1/2 definitions] |