baseline

Etymology

base + line

noun

1. 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, page 176
3. (typography) A line used as the basis for the alignment of glyphs.
   Several characters typically have descenders below the lower baseline.
4. (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) A configuration of software, hardware, or a process that is established and documented as a point of reference.
   The baseline configuration includes unsupported components.

verb

1. (engineering, computing) To provide a baseline for measurement.
   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, page 320
2. (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, page 260