base‧line /ˈbeɪslaɪn/ noun [countable usually singular]

1. technical a standard measurement or fact against which other measurements or facts are compared, especially in medicine or science:
The company’s waste emissions were 14% lower than in 1998, the baseline year.

2. the line at the back of the court in games such as tennis or volleyball

3. the area that a player must run within, on a baseball field

[TahlilGaran] Dictionary of Contemporary English ▲