- A line is a mark that is long, straight and very thin.
- She drew a line down the middle of the page to divide the page into two parts.
- A line is a row.
- Put the buttons in a straight line on the front of the shirt.
- A line is a row of people who are waiting for something in order; a queue.
- You got here last, so you have to stand at the back of the line.
A gray line
People standing in line
Definitions 1–3 take the preposition "up" ("line up")
- Someone lines things up when they put them in a straight line or row.
- Someone lines something up when they put it just in the right place or at the edge of something.
- Line up the end of the piece of wood with the edge of the table.
- Someone lines up when they start waiting in a line (queue) with other people.
- Everyone line up here, please, and I'll help you one at a time.
- Someone lines something when they mark it with one or more lines.
- Please line the pitch before the match.
- Someone lines something when they add an inside layer of material (liner) to it.