- [countable]
an object or a sign that shows the position of something （表示方位的）标记，记号 - [singular] a marker (of/for something)
a sign that something exists or that shows what it is like 标志；标识；表示 - (British English also marker pen)
a pen with a thick felt tip 记号笔；毡头笔 
- (British English) (North American English grader)
a person who marks students’ work or exam papers 阅卷人；判作业的人 - (British English)
(in team games, especially football (soccer) 团队比赛，尤指足球 a player who stays close to a player on the other team in order to stop them getting the ball 紧逼防守的队员；钉人的防守队员
Idioms
lay/put/set down a marker (for something)
to do something that sets a standard for your competitors or shows what you intend to do or achieve in the future 标志： 做一些可以为您的竞争对手树立标准的事情，或者表明您将来打算做或要实现的目标The reigning champions laid down a marker with a 36–0 defeat of their opponents. 卫冕冠军以36比0击败对手奠定了基础。 The prime minister has put down a marker for a Washington visit in May. 首相已经为5月份的华盛顿之行做好了准备。