in line

blur the line

To minimize or erode the distinction between two things.

bottom line

The summary or result; the most important information.

bottom of the line

The worst or lowest quality on the market, especially among a range of products.

bright line

A clear distinction in the context of a legal, moral, ethical, or analytical judgment.

cross the line

To overstep a boundary, rule, or limit; to go too far or do something unacceptable.

draw a line

To delimit a boundary or border.

draw the line

To set a boundary, rule, or limit, especially on what one will tolerate.

drop someone a line

To write and send (someone) a note or telegram.