thoughtless
uncaring
unthinking
airy
arbitrary
boorish
brash
caddish
capricious
careless
casual
coarse
crude
cursory
degage
disregardant
disregardful
easygoing
flippant
forgetful
free and easy
hasty
heedless
hotheaded
ill-advised
ill-bred
ill-considered
ill-contrived
ill-devised
ill-gauged
ill-judged
impolitic
improvident
imprudent
inadvertent
inadvisable
inattentive
incautious
inconsiderable
indifferent
indiscreet
inexpedient
injudicious
insensate
chivalric
godly
hard-hearted
hot-headed
impetuous
inexcusable
intemperate
new-found
pent-up
unabated
unbecoming
unbounded
uncharacteristic
unflagging
ungovernable
unladylike
unmannerly
unquenchable
unremitting
unseemly
considerate