名詞 linebacker:

1. a defensive football player who takes a position close behind the linemen
   同義詞：line backer
2. the position of a defensive football player who plays close behind the line of scrimmage
   同義詞：line backer

1. A new or substitute offensive play called by the quarterback or a defensive formation called by a linebacker at the line of scrimmage as an adjustment to the opposing side's formation.
   改變打法一種在橄欖球爭(zhēng)球線(xiàn)上作為就對(duì)方陣勢(shì)的調(diào)整，由四分衛(wèi)發(fā)令的新的或替代進(jìn)攻打法，或由后衛(wèi)發(fā)令的防守陣勢(shì)

line.back.er

n.Football （名詞）【橄欖球】
Any of the defensive players forming a second line of defense behind the ends and tackles.
中后衛(wèi)：在邊線(xiàn)和阻截隊(duì)員之后形成第二道防線(xiàn)的任一個(gè)防守隊(duì)員

【引伸】
line.back.ing
n.（名詞）