society > armed hostility > armed forces > the Army > part of army by position > [noun] > second line (3)
A person, or company of persons, whose office it is to render help. An ally; plural allies, auxiliary troops. Obsolete.
A body supporting other armed forces, esp. troops; the second line in a battle. Usually in plural.
(see quot. 1876); also attributive; also gen., any second row or series; frequently attributive or as adj., esp. designating persons or things that…