A line placed underneath a piece of text in order to provide emphasis or to indicate that it should be viewed in italics or (in electronic documents) that it acts as a hyperlink.
The character _.
An announcement of a theatrical performance to follow, placed in an advertisement for the current one.
To draw a line underneath something, especially to add emphasis; to underscore
underline the important words in the text
To emphasise or stress something
To influence secretly.
Passing under a railway line.