under the weather

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective idiomatic Somewhat ill or gloomy.
• adjective idiomatic Somewhat intoxicated or suffering from a hangover.
• adjective idiomatic, obsolete Experiencing adversity.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective somewhat ill or prone to illness