late 14c., also frecken, probably from Old Norse freknur (plural) "freckles" (source also of Icelandic frekna, Danish fregne, Swedish frägne "freckle"), from PIE *(s)preg- (2) "to jerk, scatter" (see sprout (v.)). Related: Freckles.
"to cover with spots," 1610s, from freckle (n.). Related: Freckled (from late 14c. as "spotted"); freckling.