(hot metal printing, typography) any part of a letter which extends into the space used by another letter.
Verb
(typography, chiefly proportional font printing) To adjust the horizontal space between selected pairs of letters (characters or glyphs); to perform such adjustments to a portion of text, according to preset rules.
Noun
(archaic or historical) A light-armed foot soldier of the ancient militia of Ireland and Scotland; in archaic contexts often used as a term of contempt.