A single dash that is used to connect words to create a compound word.
an hyphen
You use hyphens to make compound words that are not recognizable in common usage.
You will not use a hyphen if you do not intend to create a compound word.
Hyphens are used to join or separate words, in order to make their meaning clearer. There are several principle uses: to split words that are too long, at the end of a printed line to separate...