General search term.
Might be referring to: when you're sombre — or somber — you're acting glum, depressed, or sad. Being sombre is the opposite of being perky or happy. This is a word that has to do with the mood of a person or event. A funeral is going to be sombre, and the people at the funeral are usually pretty sombre, too..
This is a seasonal trend that repeats every October.
This trend is forecasted to be growing in the next 2 years.