Definify.com
Webster 1913 Edition
Underline
Unˊder-line′
,Verb.
T.
1.
To mark a line below, as words; to underscore.
2.
To influence secretly.
[Obs.]
Sir H. Wotton.
Webster 1828 Edition
Underline
UNDERLI'NE
,Verb.
T.
1.
To mark with a line below the words; sometimes called scoring.2.
To influence secretly. [Not used.]