un·der·line 
(ŭndər-līn′, ŭn′dər-līn)
(ŭndər-līn′, ŭn′dər-līn)tr.v. un·der·lined, un·der·lin·ing, un·der·lines
1. To draw a line under: underlined the title of the book.
2. To emphasize; stress: The debate underlined the deep divisions within the party.
n. (ŭndər-līn′)
A line under something, such as a symbol, word, or phrase, used to indicate emphasis or italic type.