say it: BAY-slahyn
baseline is a noun meaning "an imaginary line or standard by which things are measured or compared". It carries 3 recorded senses.
an imaginary line or standard by which things are measured or compared
“the established a baseline for the budget”
the back line bounding each end of a tennis or handball court; when serving the server must not step over this line
the lines a baseball player must follow while running the bases
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for baseline come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.