Careless, heedless.

Careless, regardless.

Not mindful; unaware, oblivious; indifferent, careless, heedless. Frequently in negative constructions… With of or †for.

Heedless, careless, indifferent. Chiefly with of. Obsolete.

Unmindful.

Heedless.

Unheeding, unmindful, oblivious; careless, reckless. Obsolete.

Inattentive, heedless, careless.

Heedless.

Failing to pay due regard; heedless, indifferent, careless. Also with of, †at, †for, †to.

Without heed; paying no heed or attention; careless, inattentive, regardless.

Unheedful.

Not regarding or taking heed; indifferent.

Indifferent, heedless, inattentive. Obsolete.

Characterized by neglect or inattention; negligent, heedless, careless.

Not attentive or mindful; without regard. Frequently with of.

Not perceptive; unaware.

Heedless, careless, inattentive.

The opposite of regardful; regardless, neglectful, careless.

Unobservant, inattentive; dismissive.

Of persons, their dispositions, etc.: Not properly attentive or observant; inattentive, negligent; heedless. In quot. 1653, Not having the faculty…

Unregardful.

That does not observe or notice; unobserving.

Not giving heed; heedless, inattentive.

Not taking notice; inattentive, unperceptive.

Not attentive; not fixing or applying the mind steadily; not heedful or observant; negligent.

Paying no regard or attention; neglectful, disregarding.

Not taking care of or paying attention to something; unnoticing, unheeding. Frequently with of.

Chiefly U.S. Unmindful, heedless; unaware. With of.

(un-, prefix1 affix 1.)

Of a person: careless; indifferent, apathetic.

In nonstandard or humorous use: regardless.

Heedless, careless. Frequently used to intensify following n. describing a negative quality.

Carefree, casual; careless, thoughtless, irresponsible.