Quick answer
Hayden is a boy/girl name meaning "hay valley; hay hill".
Meaning and history
From an English surname that was derived from place names meaning either "hay valley" or "hay hill", derived from Old English heg "hay" and denu "valley" or dun "hill". Its popularity at the end of the 20th century was due to the sound it shared with other trendy names of the time, such as Braden and Aidan.
Notes and context
Usage: english