Definitions of Grimm:

noun: the older of the two Grimm brothers remembered best for their fairy stories; also author of Grimm's Law describing consonant changes in Germanic languages (1785-1863)
noun: the younger of the two Grimm brothers remembered best for their fairy stories (1786-1859)
name: A surname (common: 1 in 12500 families; popularity rank in the U.S.: #1517)