- to draw a line beneath; underscore
- to stress or emphasize
a line underneath, as an underscore
transitive verbun·der·lined, un·der·lin·ing, un·der·lines
- To draw a line under: underlined the title of the book.
- To emphasize; stress: The debate underlined the deep divisions within the party.
A line under something, such as a symbol, word, or phrase, used to indicate emphasis or italic type.
(third-person singular simple present underlines, present participle underlining, simple past and past participle underlined)
- Passing under a railway line.