Word Unit: jacent-, jacen- (Latin: to lie, to rest)
Word Unit: jani-, Janus (Latin: door, entrance; gate)
Word Unit: Janus Words + (contronyms or words which have definitions that are self-antonyms; that is, which have two meanings that are the opposites of each other)
Word Unit: jaundi-, jaun- (Latin: originally galbinus, "greenish yellow" related to galbanus, "yellow" then formed with the intrusive d; from Old French jaunice, jaunisse from jaune, "yellow")
Word Unit: jejuno-, jejun- + (Latin: the fasting [intestine], the portion of the small intestine between the duodenum and the ileum [so named because early anatomists typically found this organ to be empty in dissection]; original meaning, "hungry, not partaking of food")
Word Unit: jet-, -ject, -jecting, -jected, -jection, -jector, -jectory; jacu-, jac- (Latin: throw, send, fling, hurl, cast; gush; spurt)
Word Unit: jocu-, jocul-; jocund- (Latin: joke, joking, jesting, humorous; cheerful and full of good humor)

Related "jest; joke; wit; humor; funny" word units: faceti-; farc-; humor-; lud-; satir-.

Word Unit: Journal Index of Word Info Efforts and Achievements (listings of logs, or blogs, sharing personal stepping stones and stumbling blocks)
Word Unit: jubil- (Hebrew, jobel, literally, "ram"; from the ram's horn with which the year of celebration was proclaimed; from Latin jubilaeus (annus), "year of jubilee".)
Word Unit: jud-, judic- (Latin: decide, determine a result; declare to be; right and power to interpret the law)
Word Unit: junct-, jug-, join- (Latin: link, unite, yoke; bring together, meet, merge, engage in; combine)
Word Unit: Jupiter, words from myths (Jupiter, Iuppiter, Juppiter, or Jove, King of the Roman gods; fifth planet from the sun)
Word Unit: juris- (Latin: law)
Word Unit: jus-, just-, jur- (Latin: right, upright, equitable; legal right, law)
Word Unit: jut-, juv- + (Latin: help, give assistance)
Word Unit: juven-, juv- + (Latin: young, youthful)
Word Unit: juxta-, juxt- + (Latin: beside; close by, close to, near; adjoining; proximity; to come together, to meet)