The term 'hyphen cousin' refers to two different punctuation marks, the DASH and the endash. The DASH is a punctuation mark that is four letters long and is used to indicate a break in a sentence or to separate words in a list. The endash is a punctuation mark that is six letters long and is used to indicate a range of values or to separate words in a list. Both the DASH and the endash are related to the hyphen, which is used to join words together.