(meteorology) The boundary between two masses of air of different density and/or temperature

(nautical) A shore to weather or windward from a vessel, offering protection from the wind. / Seen from land, a shore exposed to wind. / A protection, creating a relative calm.

(idiomatic) ill or gloomy, especially from a cold or flu. / (idiomatic) Somewhat intoxicated or suffering from a hangover. / (idiomatic, obsolete) Experiencing adversity.

Suitable for use only during fair weather / (of friends, etc.) Dependable only in the absence of trouble.

(meteorology) a balloon that carries meteorological instruments aloft in order to measure, record and return data concerning atmospheric pressure, temperature and humidity

Not affected by climatic conditions; capable of normal operation regardless of precipitation, wind, sun, etc. / (figuratively) Always there when needed, reliable, dependable, loyal, faithful.

Used to inquire about the weather. / (by extension, idiomatic) Indicating a change of subject to unimportant topics.

(Britain) Undesirable weather, especially foggy or stormy weather conditions.

Beaten or harassed by the weather; worn or damaged by exposure to the weather or the outdoors, especially to severe weather.

(idiomatic) To reach the end of a very difficult situation without too much harm or damage.