A linebacker, also known as a "lineback," is an important position in American football. However, there are several synonyms for the term linebacker. One synonym is "backer," which implies that the player is a defensive back. Another synonym is "line defender," which refers to a player who defends the line of scrimmage. "Middle linebacker" is another term, which specifies the position of the player in the middle of the defensive line. Other synonyms for the term linebacker include "weak-side linebacker," "strong-side linebacker," and "outside linebacker." These terms refer to the specific position on the field that the player occupies. In general, all these synonyms refer to a defensive player who is responsible for tackling and stopping the opposing team's offense.