Insulation (noun)

1. Material used to reduce heat transfer, especially in a building.
2. Isolation from the surrounding environment, especially for the purpose of reducing noise or preserving heat.

Origin:

Late 19th century: from in- "into" + latin insula "island" + -ation.

Examples:

1. The insulation in the walls helps to keep the house warm in the winter.
2. The new insulation in the walls significantly reduced the amount of noise from outside.
3. The roof insulation is an important factor in determining the energy efficiency of a building.
4. The insulation in the walls was insufficient and needed to be replaced.
5. The floor insulation helps to preserve heat in the house during the winter months.