| n. | 1. | an imaginary line or standard by which things are measured or compared; |
| 2. | the back line at each end of a tennis court. | |
| 3. | (Baseball) the lines between bases on a baseball field along which a baseball player must run while running the bases. | |
| 4. | a measurement that represents the value of a physical quantity (such as a voltage, or a level of radioactivity) in the absence of effects from other variables in a measurement, test or experiment; a control value. | |
| 5. | any horizontal line in a plot, graph, or diagram, or on a visual display in an electronic device, used as a reference point to which other values are referred. |
| Noun | 1. | baseline - an imaginary line or standard by which things are measured or compared; "the established a baseline for the budget" |
| 2. | baseline - the back line bounding each end of a tennis or handball court; when serving the server must not step over this line Synonyms: service line | |
| 3. | baseline - the lines a baseball player must follow while running the bases |
| baseline - released version |