The hyphen (‐) is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is called hyphenation.
Hyphens ("-") are used for a wide variety of grammatical tasks
which are distinct from those of both en dashes ("–") and em dashes
("—").
Examples are the following:
Co-opted
Good- for- nothing
she has gray-green eyes
pre and post-adolescent trauma
forty- five