The phrase "big headliner" refers to a person or thing that is the main attraction or the most prominent feature of an event, show, or performance. Full definition
For his first big headliner of 2015, Black is hopping on The D Train, a comedy that popped up at Sundance and sees its first trailer debut today. (waytooindie.com)
The experts are generally not comfortable creating big headliners and exaggerations — to the degree that they get to the front pages. (dotearth.blogs.nytimes.com)
They were just a couple of the big headliners in a field that became one of the strongest of the PGA Tour regular season. (sbnation.com)