Definition

1. Noun:
   • Water in a gaseous state: "water vapor" refers to water that exists as a gas, typically invisible, in the Earth's atmosphere. It is formed by evaporation or sublimation at temperatures below water's boiling point.

Usage

• "Water vapor" is an uncountable noun used to describe the gaseous phase of water present in the air. It is a key component of humidity and is essential in meteorological processes like cloud formation.

Examples

• Noun:
  • The amount of water vapor in the air is called humidity.
  • Clouds form when water vapor condenses into tiny droplets.
  • The greenhouse effect is influenced by gases like carbon dioxide and water vapor.

Advanced Usage

• Scientific Context: In physics and chemistry, "water vapor" is distinguished from steam, which is water vapor at or above the boiling point and often visible.
  • The experiment measured the pressure of water vapor in the closed container.

Variants and Related Words

• Vapor (noun): A substance diffused or suspended in the air, especially one normally liquid or solid.
  • The cold turn caused the vapor to condense on the window.
• Water vapour (noun): The British English spelling of "water vapor".
• Steam (noun): The hot, visible mist formed by boiling water. While related, "steam" is not a direct synonym for "water vapor" in technical contexts, as it often implies visibility and higher temperature.

Synonyms

• Moisture (noun): Water or other liquid diffused in a small quantity as vapor, or condensed on a surface. (Note: "Moisture" is a broader term that can include liquid water.)
• Humidity (noun): The presence of water vapor in the atmosphere. (Note: "Humidity" specifically refers to the of vapor.)

Related Phrases

• Water vapor pressure (noun phrase): The pressure exerted by water vapor in a mixture of gases.
  • The meteorologist calculated the water vapor pressure to predict dew point.
• Water vapor content (noun phrase): The measure of how much water vapor is present in the air.
  • The air mass from the ocean had a high water vapor content.

Noun

1. water in a vaporous form diffused in the atmosphere but below boiling temperature