Rheiddyn, n. a dart, a glance
Rheiniad, n. a throwing a lance
Rheinio, v. to throw a lance
Rheitheg, n. canon of speech
Rheithfawr, a. greatly just
Rheithiad, n. a regulation
Rheithiadol, a. canonical
Rheithiadur, n. a regulalor
Rheithio, v. to fix a law
Rheithiol, a. established as law