describing the members of a sports team who play regularly at the start of a match (rather than being substituted on)

belonging to the second string of a team / substitute or replacement / second most important

belonging to the third string of a team; one who plays behind the first and second strings. / a substitute or replacement.

(idiomatic) Of a decidedly lower quality or condition.

(sports) A unit of players that plays behind the first and second strings; a junior varsity team.

Alternative spelling of G-string

(physics) A candidate unified theory of all physical forces and particles; a theory which suggests that subatomic particles are one-dimensional strings rather than zero-dimensional points. It also suggests that space-time can have up to nine dimensions, plus the dimension of time.

aerosol string

(horticulture) A powered, hand-held garden implement that uses a rotating monofilament line to cut grass, etc., without damaging other objects.

(transitive, idiomatic) To keep somebody falsely believing that one has certain intentions.