Mulligrubs is a term for a state of low spirits or a mild form of depression, often accompanied by a gloomy outlook on life. It's like a case of the emotional blahs, when everything seems a bit gray and unexciting.
Usage Example 1: "After a tough day at work, Sarah was suffering from the mulligrubs and just wanted to curl up with a good book and a cup of tea."
Usage Example 2: "Tom's constant mulligrubs made it challenging for his friends to plan fun outings, as he always seemed uninterested and downcast."