A line that is a base for measurement or for construction.
A laser level generates a convenient baseline for interior work.
2
A datum used as the basis for calculation or for comparison.
We used the last doctor visit to provide baselines for vital statistics.
Currently, about fifty million square miles of land on the planet are ice-free, and this is the baseline that's generally used for calculating human impacts.2014, Elizabeth Kolbert, The Sixth Extinction: An Unnatural History, Picador, →ISBN, page 176:
Several characters typically have descenders below the lower baseline.
4
Hobbies, Lifestyle, Sports, Tennis The line at the farthest ends of the court indicating the boundary of the area of play.
The umpire missed the call. The ball hit the baseline.
5
Engineering, Natural sciences, Physical sciences A configuration of software, hardware, or a process that is established and documented as a point of reference.
The baseline configuration includes unsupported components.
Finally, the test was baselined by evaluating the best and poorest catalysts of their respective types by this protocol.1993, M.M. Mitchell et al., “Residual Feed Cracking Catalysts”, in Magee & Mitchell, editors, Fluid Catalytic Cracking, →ISBN, page 320:
To ensure Lojban remains stable while people learn it, the language definition is being closely controlled; the grammar and core vocabulary have already been baselined (frozen) for several years.2025 October 14 (last accessed), “Chapter 1. Questions and Answers on Lojban”, in lojban.org:
2
Hobbies, Lifestyle, Sports, Tennis To play from the baseline.
By the time Maggie, who is eight years younger than Manuela, started playing, baselining was no longer enough to win points, so she learned to move around the court more …2002, Susan Orlean, The Bullfighter Checks Her Makeup, →ISBN, page 260: