justifier

In printing: The wooden wedge once used in old forms of hand-press to keep together parts about to separate.

One who justifies; one who vindicates, supports, defends, or upholds; also, one who pardons and absolves from guilt and punishment.

In printing: The workman who makes of just length, and with just spaces between the words, the lines of type set by a type-setting machine.

An attachment to a type-setting machine which does automatically some or all of the work of justification.

In type-founding, the workman who fits up a suite of strikes or unjustified matrices for use on one mold, making each and all just or uniform in height as to body, of even line as to face, and of proper nearness to mated letters.

One who justifies; one who vindicates, supports, defends, or absolves.

One who, or that which, justifies (some belief or action).

a person who argues to defend or justify some policy or institution