informal, natural, unconventional, and careless
insolent, impudent, impertinent, and flippant
integrity, frankness, sincerity, and truthfulness
intellectual, moral, emotional, and esthetic
intense, earnest, violent, and extreme
invent, discover, design, and contrive
inveterate, confirmed, chronic, and obstinate
invidious, envious, odious, and offensive
invincible, unconquerable, insurmountable, and insuperable
irksome, tiresome, tedious, and annoying
irregular, uncertain, devious, and unsystematic
irritable, choleric, petulant, and susceptible
J
jangle, wrangle, squabble, and quarrel
jealousy, suspicion, envy, and watchfulness
joyful, lively, happy, and hilarious
judgment, discrimination, penetration, and sagacity [sagacity = farsighted; wise]
just, impartial, equitable, and unbiased
juvenile, childish, trifling, and puerile [puerile = immature; childish]
K
keen, intelligent, penetrating, and severe
keep, protect, support, and sustain
kind, sympathetic, ready, and appreciative
kingly, noble, imperial, and august
knowledge, learning, enlightenment, and understanding
L
lapses, makeshifts, delays, and irregularities
lawful, legitimate, allowable, and just
lazy, listless, drowsy, and indifferent
lightly, freely, unscrupulously, and irresponsibly
lively, vivacious, vigorous, and forcible
loss, deprivation, forfeiture, and waste
loud, noisy, showy, and clamorous
loutish, prankish, selfish, and cunning
love, depth, loyalty, and faithfulness
lucidity, impressiveness, incisiveness, and pungency [pungency = to the point]
M
malice, anger, uncharitableness, and indignation
malignity, brutality, malevolence, and inhumanity
manners, morals, habits, and behavior
marvelous, wonderful, extraordinary, and incredible
massive, ponderous, solid, and substantial
mastery, proficiency, dexterity, and superiority
matchless, unrivaled, inimitable, and incomparable
maxim, proverb, truism, and apothegm [apothegm = terse, witty, instructive saying]
medley, mixture, jumble, and hodge-podge
meekness, inwardness, patience, and self-denial
merciless, remorseless, relentless, and ruthless