first string

adjective

1. composed of regular members, participants, etc. (distinguished from substitute): the first-string team.
2. foremost; main: the first-string critics.

noun

1. the top player of a team in an individual sport, such as squash

adjective first-string

2. being a regular member of a team rather than a substitute or reserve
3. being the top player of a team in an individual sport
4. of high rating; first-class