late Old English rudig "rubicund," probably from rudu "redness," related to read "red" (from PIE root *reudh- "red, ruddy"). As a British slang euphemism for bloody (q.v.), first recorded 1914. Related: Ruddiness.
a ruddy complexion
rucksack
ruckus
ruction
rudder
ruddock
ruddy
rude
rudely
rudesby
rudiment
rudimentary