admonitor

plural admonitors

1. An admonisher; a monitor.

   Conscience is […] at most times a very faithful and a very prudent admonitor.

   1764, William Shenstone, “Essays on Men, Manners, and Things”, in The Works in Verse and Prose of William Shenstone, volume 2, London: R. & J. Dodsley, page 307

   2 more examples

   But as a wyckyd person he contemnyd all admonicions, desirid to finishe his treyterons purpose, and after that he had eatyn of that holy supper, he depertyd out of Christes companye, and with all dil[i]gence sowght how to haue his admonitour slaine.

   1547, John Hooper, An Answer vnto my Lord of Wynthesters Booke Intytlyd a Detection of the Deuyls Sophistrye, Zurich: Augustyne Fries

   […] mens hearts rise and swell against faithful Admonitors, and they must not be reproved or contradicted.

   1673, Urian Oakes, New-England Pleaded With, Cambridge: Massachusetts, page 35