Main Entry:

base·line

Pronunciation:

\ˈbās-ˌlīn\

Function:

noun

Usage:

often attributive

Date:

1610

1: a line serving as a basis ; especially : one of known measure or position used (as in surveying or navigation) to calculate or locate something2 a: either of the lines on a baseball field that lead from home plate to first base and third base and are extended into the outfield as foul lines b: base path3: a boundary line at either end of a court (as in tennis or basketball)4: a usually initial set of critical observations or data used for comparison or a control5: a starting point <the baseline of this discussion>