Originally: any of several Japanese cypresses constituting the former genus Retinispora (later spelt Retinospora), now included in Chamaecyparis; (also, in form Retinispora or Retinospora) the genus itself. In later use: any of various (varieties of) trees and shrubs of the genus Chamaecyparis and allied genera having permanently juvenile (needle-like) foliage, especially grown for ornament or as hedging.