- a name between a person's first name and surname
- a characteristic quality for which a person is known: caution is my middle name
WordReference Random House Unabridged Dictionary of American English © 2020
the part of a person's name occurring between the first and family names, as a second given name or a maternal surname.
- 1825–35, American.
Collins Concise English Dictionary © HarperCollins Publishers::
middle name n
'middle name' also found in these entries: