aider

plural aiders

1. A person who aids or assists.

   The woman in question had, as she said, been a close friend of Margaret’s, and, as such, an aider in her habits of intemperance.

   1898, Paul Laurence Dunbar, chapter III, in The Uncalled: A Novel, New York, N.Y.: Dodd, Mead and Company, →OCLC, page 23

   3 more examples

   The capitaines of the toune seyng theire pillers borken, and their chief ayders discomfited, rendered the toune to the duke of Somerset,

   1548, Edward Hall, “The trobleous season of Kyng Henry the sixt, The .xv. yere”, in Hall’s Chronicle, London: Richard Grafton

   […] arte is neither an aider nor a surmounter, but onely a bare immitatour of natures works, following and counterfeyting her actions and effects […]

   1589, George Puttenham, The Arte of English Poesie, London: Richard Field, Book 3, Chapter 15, p. 254

   […] being there as an assistant, he actually seemed—[…]—to be the aider and abettor of a system which filled him with honest disgust and indignation, […]

   1838 March – 1839 October, Charles Dickens, “Of the Internal Economy of Dotheboys Hall”, in The Life and Adventures of Nicholas Nickleby, London: Chapman and Hall, […], published 1839, →OCLC, page 73

2. climbingA mountaineer's stirrup or étrier.

   As I was switching my feet in my aiders, the hook popped.