Part 1.
jet
an airplane powered by gas turbines
jibe
be compatible, similar, or consistent
jocund
full of or showing high-spirited merriment
junket
a trip taken by an official at public expense
justify
show to be reasonable or provide adequate ground for
keen
demonstrating ability to recognize or draw fine distinctions
Part 2.
kindle
catch fire
knack
a special way of doing something
knight
a person of noble birth trained to arms and chivalry
knoll
a small natural hill
labor
any piece of work that is undertaken or attempted
laggard
someone who takes more time than necessary
Part 3.
lancet
a surgical knife with a pointed double-edged blade
languid
lacking spirit or liveliness
larder
a small storeroom for storing foods or wines
largesse
liberality in bestowing gifts
latitude
freedom from normal restraints in conduct
league
an association of sports teams that organizes matches
Part 4.
level
a relative position or degree of value in a graded group
levity
a manner lacking seriousness
liberal
having political views favoring reform and progress
libertine
a dissolute person
libretto
the words of an opera or musical play
lineament
the characteristic parts of a person's face