Definition of adherency in US English:

adherency

noun

archaic
  • 1The action, state, or fact of adhering to a person or thing; especially steadfast support, allegiance. Also occasionally: an instance of this.

  • 2A group of adherents or supporters; a following. rare after 17th cent.

Origin

Late 16th century; earliest use found in Geoffrey Fenton (c1539–1608), translator and administrator in Ireland. From post-classical Latin adhaerentia adherence; compare -y, -ency. Compare earlier adherent.