Meaning and Name Origin
Mortimer \m(o)-rti-mer, mor-timer\ as a boys' name is of Old French origin, and the meaning of Mortimer is "dead sea". From "morte mer". Baronial surname that probably referred to a stagnant lake on the family's lands. First used since the 19th century. Entrepreneur Mortimer Zuckerman.
Mortimer is an uncommonly occurring given name for males but a very prominent last name for both adults and children (#5702 out of 88799, Top 6%). (2000 U.S. Census)
Shown below is the baby name popularity of Mortimer for boys. Mortimer reached its peak position of #611 in the U.S. then, but is not ranked at the moment. (2014 Birth Statistics)