D defs.my
Entry 3 senses Webster, 1913

Insulation

/ĭnˌ-səl-āsh'-ən/ · In·su·la·tion · IPA /ˌɪnsəˈleɪʃən/
01 n. The act of insulating, or the state of being insulated; detachment from other objects; isolation.
  1. 1.
    The act of insulating, or the state of being insulated; detachment from other objects; isolation.
  2. 2.
    The act of separating a body from others by nonconductors, so as to prevent the transfer of electricity or of heat; also, the state of a body so separated.(Elec. & Thermotics)
  3. 3.
    The material or substance used to insulate from either electrical or thermal conduction; as, fiberglass is used as thermal insulation in the walls and roofs of houses.