A person who or thing which wanders at night; a night traveller.
Origin
Late 16th century; earliest use found in Abraham Fleming (c1552–1607), author, literary editor, and Church of England clergyman. From night + wanderer.
Definition of night wanderer in US English:
night wanderer
nounˈnʌɪt ˌwɒnd(ə)rə
A person who or thing which wanders at night; a night traveller.
Origin
Late 16th century; earliest use found in Abraham Fleming (c1552–1607), author, literary editor, and Church of England clergyman. From night + wanderer.