I. | ̷ ̷ ̷ ̷| ̷ ̷ transitive verb
Etymology: under (I) + line (to cover inner surface of)
: to provide with an underlining
collar underlined with black — advt
II. transitive verb
Etymology: under (I) + line (to mark with a line)
1.
a. : to mark (a word) with a line underneath : underscore
b. : to put emphasis upon : stress in or as if in utterance
underlines the unity of knowledge and the consequent unity which should be aimed at in education — R.M.Hutchins
2. : to make evident the significant character or importance of
British weakness was underlined when the French fleet escaped from Toulon — J.H.Plumb
hydrogen bomb explosions underlined in a horrifying fashion the likely consequences of atomic attack — Barbara Ward
3. : to announce in advance by or as if by an underline
his book is underlined for publication next month
III. ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ noun
1.
a. : a horizontal line placed underneath something
words with a single underline are to be set in italics
b. underlines plural : a set of guiding lines placed underneath a sheet to be written on
2.
a. : explanatory or descriptive wording underneath an illustration : legend
b. : a line placed below the notice of a current performance announcing a performance shortly to follow
3. : the outline of the lower part of an animal's body between the front and rear legs
underline well tucked up
also : the ventral surface of a quadruped's body
brown above, with the underline lighter