jur/jus

law; swear an oath

Spelled jur, jus, jud · jus (stem jur-) 'law, right'; jurare 'swear an oath'

Romans swore by jurare: a juror swears an oath, perjury breaks one, and abjuring means swearing something away.

Words built from it

abjure — Formally give up a belief, claim, or practice.
ab- (away) + jur (swear an oath)
perjury — The act of deliberately lying under oath.
per- (wrongly) + jur (swear an oath) + -y (action or result)
adjudicate — Make a formal judgment about a dispute.
ad- (toward) + jud (law) + -ate (make)
jurisdiction — The legal authority to make decisions, or the area that authority covers.
jur (law) + dict (declare) + -ion (action or result)
justice — Fair treatment and the proper application of law.
jus (law) + -ice (quality)
juror — A member of a jury who has sworn to consider a case fairly.
jur (swear an oath) + -or (one who)
conjure — Call something forth, especially by magic or imagination.
con- (together) + jur (swear an oath)

Jurassic — Contains jur, but names the Jura Mountains, where rock of that period was first described; nothing to do with Latin jus, juris (law).