throng in

(v) : (transitive, informal) To add something extra free of charge.

(v) : (transitive, informal) To include in a calculation.

(v) : (idiomatic) To quit, to fold.

(v) : Used other than figuratively or idiomatically: see throw, in.

(v) : (transitive, archaic) To inject, as a fluid.

(n) : Alternative form of throw-in. [(soccer, rugby, basketball, handball) A set-piece where the ball is thrown back into play]