Your word for today is: adjutator, n.
Pronunciation: Brit. /ˈadʒᵿteɪtə/, U.S. /ˈædʒəˌteɪdər/
Etymology: < classical Latin adiūtāt-, past participial stem of adiūtāre to help, assist (see adjutant adj.) + -or suffix, probably originally as alteration of agitator n. (compare agitant n. 1). Compare post-classical Latin adiutator (6th cent.). Compare earlier adjutor n.1 (especially quot. 1642 at that entry), and (with the later use in the general sense ‘helper, assistant’) later coadjutator n.
Now chiefly hist.
A person empowered to act on behalf of others; spec. each of the delegates chosen to represent the private soldiers of some units of the Parliamentary army during the English Civil War, initially at the Army Council of June 1647 (cf. agitator n. 2). Later also (occas.) more generally: a helper, an assistant.
1647 Petition Private Souldierie 29 May in T. Fairfax Two Lett. with Advice Councel of Warre sig. B2, Your Excellencies and the Kingdomes innocent and faithfull servants, whose names are hereunto annexed, being Agitators in behalf of the severall Regiments. Edward Sexby. Edward Taylor. Adjutators of the Generals Regime[nt] of Horse [etc.].
1647 R. Overton (title) Eighteene reasons propounded to the soldiers of the body of the army, why they ought to continue the several adjutators of their respective regiments, troopes, and companies, for the good of the Army, Parliament and Kingdome.
1648 F. Wortley Mad Tom a Bedlams Desires of Peace (single sheet), Blesse those few Lords are honest, From the Armies Adjutators, Saints sent from heaven, to make all even, Both Church and State translators.
1660 C. Southaick Fames Genius (single sheet), Then from the North That grand Adjutator came, Whose approbation gave him the best name.
1713 E. Ward Hist. Grand Rebellion II. 426 The Officers..did themselves the weighty Point debate, Chusing their Adjutators from among The scoundrel Class of the Bellonian Throng.
1794 C. Coote Hist. Eng. VI. xiii. 345 Subalterns and privates, chosen out of each regiment as representatives of the army, under the title of agitators. [Note] Called adjutators by some writers.
1826 Scott Woodstock II. xv. 229 The corporal had been one of the adjutators or tribunes of the common soldiers.
1832 E. Duros Otterbourne II. vi. 126 Him, he intended to make his companion and minor adjutator.
1876 J. R. Green Short Hist. Eng. People 548 The Adjutators had taken a step which put submission out of the question.
1940 H. T. Lowe-Porter tr. T. Mann Beloved Returns vi. 275 He will feel the loss of his familiar helper and excellent adjutator, when you leave his house.
2004 Law & Hist. Rev. 22 4 In November 1647..one of his [sc. Charles I's] supporters had been assured by an army adjutator that [etc.].