An implement, an instrument or apparatus designed (or at least used) as a means to a specific end, especially:
(obsolete) The act of applying.
1658, Elias Ashmole, The Way to Bliss, London: Nath. Brook, Book 2, Chapter 2 “Of Health,” p. 75,
[…] there be three things, and every one full of under-branches belonging to this Art and way of Healing: The first is knowledge of the Diseases: the second is the Remedies against them: and the third of the appliance of Remedies; All which should be traversed in this Discourse.
(obsolete) A means of eliminating or counteracting something undesirable, especially an illness.
c. 1775, Thomas Hull, Moral Tales in Verse, London: George Cawthorn, 1797, Volume 2, “The Advantages of Repentance,” pp. 161-162,
With charitable care
They rais’d him up, and, by appliance meet,
Quicken’d the pulse, and bade it flow anew.
(obsolete, rare) Willing service, willingness to act as someone wishes.