Jaded
tired by excess or overuse, slightly cynical
Jargon
nonsensical talk, specialized language
Jeopardize
expose to injury
Jest
to act playfully
Jettison
to discard, to get rid of as unnecessary or encumbering
Jingoism
belligerent support of one’s country
Jocular
playful, humorous
Jollity
cheerfulness, liveliness, celebration
Jubilation
joy, celebration
Judicious
sensible, showing good judgment
Juggernaut
huge force destroying everything in its path
Juncture
point of time, especially where two things are joined
Junta
a small governing body, especially after a revolutionary seizure of power
Jurisprudence
philosophy of law
Justify
to prove valid
Juxtaposition
side-by-side placement